Harry earned d dollars mowing lawns. He put 20% of his earnings in the bank and paid back $50.00 to his father. He spent one-fifth of the remaining money on a video game. Which expression represents the amount he spent on the video game?
(0.20 - 10) dollars
(0.20 - 50) dollars
(0.160 + 10) dollars
(0.160 - 10) dollars

(0.16d - 10) dollars

Step-by-step explanation:

"Harry earned d dollars mowing lawns. He put 20% of his earnings in the bank and paid back $50.00 to his father."

Start with d dollars.

He put 20% of d dollars in the bank. 20% of d is the same as 0.2d.

Now he has d - 0.2d = 0.8d

He paid his father $50.

Now he has 0.8d - 50

"He spent  one-fifth of the remaining money on a video game. Which expression represents the amount he spent on the video game?"

He spent 1/5 of 0.8d - 50 on a video game, so he spent on the video game:

1/5 * (0.8d - 50) = 0.16d - 10

0.16d - 10 dollars

(You forgot the "d" in the answers."

5

step-by-step explanation:

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204