8x + 7y = 2
8x + 3y = 10

Answer:

1) -9.3465 × 10^8

2) 1.6214 × 10^-1

3) 1.33 × 10^-11

Explanation:

When solving arithmetic operations of numbers in scientific notation, there is a strategy that can be used.

First recognize the quotient(division) between the size of the numbers indicated by a multiple of 10 to a certain power. Remember, taking the quotients of like numbers with different powers is the subtraction of powers.

For example, to solve the first expression (problem one):

7.35 x 10^6 – 9.42 x 10^8

Divide 10^8 by 10^6 to get 10^2

So

it is like subtracting 7.35 and 9.42 × 10^2 which is 7.35 - 942, then once this expression is solved, multiply by the lowest multiple of 10 which is 10^6.

7.35 - 942 = -934.65 → -934.65 × 10^6 = (-9.3465 × 10^2) × 10^6 = -9.3465 × 10^8.

Long subtraction may need to be used when dealing with numbers that are far apart. Likewise long addition multiplication or division is used for very big or small numbers.

Anyway for the second expression (problem 2)

Addition in my opinion is much easier because it is really just adding on the bigger number. Subtraction may take a little longer but both processes are all based on the bigger number or the number with the greatest power of the multiple 10.

So 3.14 × 10^-3 + 1.59 × 10^-1

The quotient between 10^-1 and 10^-3 is the the difference between -3 and -1 which is 10^2

So again it is like adding 3.14 and 1.59 × 10^2 which is 3.14 + 159 = 162.14 = 1.6214 × 10^2. Now use the multiple of 10 with the largest contrast which is 10^-3 so 1.6214 × 10^2 × 10^-3 = 1.6214 × 10^(2-3) = 1.6214 × 10^-1.

Answer:

3 medium and 2 large pizzas.

Step-by-step explanation:

70= 2.5+(12.50x+15y)

70-2.5=67.5

Possibilities

67.5=12.5(1)+15(4) FALSE(72.5)

67.5=12.5(4)+15(1) FALSE (65)

67.5=12.5(2)+15(3)FALSE(52.5)

67.5=12.5(3)+15(2)

TRUE (67.5)

Answer:

22.68 or 22.7

Step-by-step explanation:

hope this helps

Answer:

23

My logic:

Well i just rounded up to the nearist one because you didn't specify how to round.

y=4.5x the equation for cranberries

Step-by-step explanation:

So the easiest way to solve this would be take the $18 and divide it by the 4 pounds you then get the unit price per pound which is $4.5 a pound

Answer:

x = 3 and -1

Step-by-step explanation:

5(x²-2x-3)

(x-3)(x+1)

Answer:

Zero's are: x= 3, -1

Step-by-step explanation:

With factoring, and determining the middle ground, finding the zeroes will come back to this result.

Answer:

b is 10.5 c is 11

Step-by-step explanation:

9+1.5

10.5

3(5)-4

15-4

11

Answer:

I think its 183 1/3

It's what I figured out & the other answer says the same.

Step-by-step explanation:

You like TommyInnit, too? Poggers! <3

Answer:

183 1/3

Step-by-step explanation:

I'm assuming that x and y are directly proportional.

So anyways:

5.5 divided by 3/4 is 7 1/3.

Because this is directly proportianol, you'll also have to mutiply y by 7 1/3.

So: 25 times 7 1/3 equal to 183 1/3

Hope this helps!

Answer:

76

Step-by-step explanation:

Answer: 4

Step-by-step explanation:

If you multiply 5x-2 you will get -10

Do all the steps and you get 4

Therefore your answer is 4.

Answer:

Step-by-step explanation:

7x + 14 = 8.4x

14 = 1.4x

x = 10 hours

Each works 10 hours. Their total is 84 dollars each.

Answer:

(D) 24°

Step-by-step explanation:

(5x + 6)° + (3x)° + (142 - 4x)° = 180°

5x + 6 + 3x + 142 - 4x = 180

4x + 148 = 180

4x = 32

x° = 8°

m∠E = 3×8° = 24°

Answer:

13.m<9=110  14.m<4=115    15.m<10=70   16.m<11=70   17.m<8=65    18.m<5=65  19.m<3=65      20.m<14=110

Step-by-step explanation:

Answer:

ANSWERS ARE B, C, AND D.

Step-by-step explanation:

I found the unit rate of 350 and 5, because we can use a calculator (as stated on top) I just punched in 350 divided by 5 and got 70. Now i know this may not sound that "professional", but nothing needs to always be professional as long as its efficient and most importantly gets you the right answer. I then took the time to multiply each number, (the ones on the left : 3, 3.5, 6, 7.25, and 8) by 70. If the answer you got on the calculator match up to the number on the right, (240, 420, 507.50, and 490) its correct, if it doesn't match up, you can tell that its most likely not the answer. You should end up with three answers that all end up having the unit rate of 70. Hope this helps anyone who needed it.

ANSWERS ARE B, C, AND D.

Answer:

The answer is B,C, And D

Step-by-step explanation:

I just saw it on Khan and got it right.

Answer:

2n

Step-by-step explanation:

Pythagoras [tex]a^{2} + b^{2} = c^{2}[/tex]

2 squared plus 2 squared = 8 but you need to find out the root of 8,

square root of 8 is a surd, so answer in that

Answer:

4n

Step-by-step explanation:

a^2+b^2=c^2

2n^2+2n^2=c^2

4n^2=c^2

sqrt 4n^2=sqrt c^2

4n=c

Answer:

y=-21/17

Step-by-step explanation:

Answer:

y= - 21/17

Step-by-step explanation:

2(15+6y) +5y =9

2(6y+15)+5y=9

2(6y +15) +5y=9

12y+30 + 5y = 9

12y+30+5y =9

17y+30 =9

17y+30 =9

17y +30 -30 =9-30

17y=-21

y=-21/17

Answer:

D. About 2700 in^2

Step-by-step explanation:

The area of a circle A = πd²/4 where d = diameter of circle.

A/d² = π/4 = k the proportionality constant.

So, A₁/d₁² = A₂/d₂² Now for circle A, Area = A₁ = 300 in² and diameter = d₁ = 20 inches. For circle B, Area = A₂ = unknown and diameter = d₂ = 60 inches.

So, we have

A₁/d₁² = A₂/d₂²

A₂ = A₁d₂²/d₁²

A₂ = A₁(d₂/d₁)²

substituting the values of the variables, we have

A₂ = 300 in²(60 in/20 in)²

A₂ = 300 in²(3)²

A₂ = 300 in²(9)

A₂ = 2700 in²

So, the area of circle B is about 2700 in²

Answer:

881 (-6x)

Step-by-step explanation:

Answer:

875

Step-by-step explanation:

Answer:

Simply line it up and divide it.

Then you get the answer:

875

Answer:

7 days

Step-by-step explanation:

Given that:

Distance tunneled into the ground each day = 2cm

The rate is the same everyday ;

Hence, to. Tunnel 14cm into the ground , it will take the earthworm;

1 day = 2cm

x days = 14cm

Cross multiply :

2x = 14

x = 14 /2

x = 7

Hence, it will take 7 days for the earthworm to tunnel 14cm

Answer:

Vertex is (-1, -9)

Step-by-step explanation:

To find the x-value of the vertex, we use the formula

x

=

−

b

2

a

(This is considered the axis of symmetry).

a

=

1

and

b

=

2

with

c

=

−

8

(These are the numbers in order)

By substituting we get

x

=

−

(

2

)

2

⋅

1

, which simplifies to

x

=

−

1

.

Once you find x, substitute back into the equation to find y.

y

=

(

−

1

)

2

+

2

(

−

1

)

−

8

y

=

1

−

2

−

8

y

=

−

9

Putting the two numbers together you get the coordinates

(

−

1

,

−

9

)

.

Answer:

1;3;5;7;11;13;17;19 add all the number

Answer:

Step-by-step explanation:

Prime numbers less than 21 are

2, 3,5,7,11,13,17,19

Sum= 79

Answer:

top left is "same" top right is "parallel"

Answer:

i need help on this question too

Step-by-step explanation:

Answer:

I think X=10 but im not for sure.

Step-by-step explanation:

150 (X+10) = 200 (X+5)

150x+1500   200X+1000

-150X            -150X

1500               50X+1000

-1000                      -1000

500                50X

50                   50

10=X

Lo siento mucho, no hablo muy bien español ... ¡Ojalá pudiera! Sería mucho más útil de esa manera

Answer:

[tex]f^{-1}(x) = x/2 +2[/tex]

Step-by-step explanation:

let [tex]f^{-1} (x)[/tex] = y

then f(y) = x

2y-4 =x

2y =x+4

y= x/2 +2

hence f^{-1} (x) = x/2 +2

Answer:

the anser is 64 cups

Step-by-step explanation:

half gallon is 8 cups and she bought 8 of them so multiply 8 and 8 or 8^2 and you get 64

pls mark brainliest

Answer:

A. 64 cups

Step-by-step explanation:

There are 16 cups per gallon, so a half gallon would be 8 cups. If she bought 8 bottles that means you must take the 8 bottles times the 8 cups per bottle or just 8*8=64. Answer A. is 64 cups.

If this helped you, which I hope it did, please click the thanks button below.

Thank you! :-D

Answer:

a ball bouncing off a wall

Step-by-step explanation: