The geometric mean of two numbers x and y is √(xy).

So, if the geometric mean of 3 and a is 9 =>

9 = √(3a)

=> 9^2 = 3a

=> a = 9^2 / 3

a = 81 / 3

a = 27

Answer: the value of a is 27.

4 0

3 years ago

How to solve y in -(y+9)=10

Allisa [31]

Answer:

Step-by-step explanation:

- (y+9) = 10

Multiply through by -1 gives us

y+9 = -10

Subtract 9 from both sides

y = -19

That's your answer.

If you work it through it satisfies the equation.

That is:

- (-19 +9) = 10

-(-10) = 10

10 = 10

Boo ya!

5 0

2 years ago

A local food mart donates 20% of it's friday's sales to charity.

Digiron [165]

Answer:

$64

Step-by-step explanation:

We have been given that a local food mart donates 20% of it's Friday's sales to charity. This Friday the food mart had sales totaling 320.00 dollars.

To find the the amount donated to the charity, we will find 20% of $320.

$\text{The amount donated to the charity}=\$320\times\frac{20}{100}$

$\text{The amount donated to the charity}=\$320\times0.20$

$\text{The amount donated to the charity}=\$64$

Therefore, $64 were donated to the charity.

5 0

3 years ago