8/9=?/36 15:18=5:? ? to 7 = 9 to 21

Problem 1

Work Shown:

8/9 = x/36

36*8 = 9x

288 = 9x

9x = 288

x = 288/9

x = 32

Problem 2

Work Shown:

15:18 = 5:x

15/18 = 5/x

15x = 18*5

15x = 90

x = 90/15

x = 6

Problem 3

Work Shown:

x to 7 = 9 to 21

x/7 = 9/21

21x = 7*9

21x = 63

x = 63/21

x = 3

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225

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