I know the answer is 20 but I can't figure out how to write the equation

I know the answer is 20 but I can't figure out how to write the equation

Solve each system of inequalities by graphing. x+2y<10, x+2y>9. Both <> have line under them

Divide and simplify to the form a+bi 7/4-9i

3y-x=-3 y=-2x+6

estimate 42 squared to the nearest 10th what 2 integers is 42 squared between one cell phone company charges 20 dollars plus 15 cents per min used write and...

If y varies inversely as x, and y equals=13 when x equals=3, find y when x equals=6.

If x varies directly as y, and x equals=16 when y equals=4, find x when y equals=10.

The current in a circuit varies inversely as the resistance. The current is 18 amperes when the resistance is 2 ohms. Find the current for a resistance of 15 ohms.

I want to be able to rearrange the equation so that the constant B is removed form the sine component of the following summation. Example (i=1 to n) Σ sin(Bxi)cos(BXi) = 0? I...

((x+3)/(x2-3x-28)) - ((2)/(x2-49))

A wheelchair company determines that the cost of manufacturing them follows the cost equation , where C = Total Cost and x = number of wheelchairs manufactured. a. The 500,000 represents...

{-2y+2x=3 {-5y+5x=12

Explain why it is possible for a line to have no equation in point-slope form or to have infinitely many, but it is not possible that there is only one.

A group of scientists studied the effect of a chemical on various strains of bacteria. Strain A started with 12000 cells and decreased at a constant rate of 4000 cells per hour after the chemical...

Sven has been on a diet for a couple of months now. When he got on the scale this morning, he weighed in at 242.4 lbs, a marked improvement over the 252 lbs that he weighed 16 days ago. (a)...

The price of an item with tax is equal to the price of the item plus 1/20 of the price. Write a rule for the price with tax. Write ordered pairs for the price with tax of items that cost $2, $15,...

Fireworks are discharged vertically upward from a height of 4 feet above the ground. Its path is given by, h = -16t2 + 160t + 4, where h is the height of the fireworks in feet and t is...

log base 4 of (2X) + log base 4 of (X+7)=2 Do I need to check for extraneous? Why doesn't the answer -8 work?

1. b2 * b5 = b10 2. 42 * 43= 142+3 = 145 3. (x6)3 = x6+3 = X9 4. (5X)2 = 5X2 5. (a9/a3) = a9/3 =a3 6. (45/23) = 25-3...

It is an collage math algebra problem