Remark
Are you sure you don't mean that (x - 7) is squared? The way you have written it indicates that it is squared. I'll treat it that way and you can leave a not if I am wrong.
Solution
(x - 7)^2 - 25 = 0 Add 25 to both sides
(x - 7)^2 - 25 + 25 = 25 Combine the left
(x - 7)^2 = 25 Take the square root of both sides.
sqrt(x - 7)^2 = sqrt(25)
x - 7 = +/- 5 Add 7 to both sides
x = 7 +/- 5
=========
x1 = 7 + 5
x1 = 12
x2 = 7 - 5
x2 = 2
Smallest x = 2
Largest x = 12
Answer:
4x² + 20x - 2
Step-by-step explanation:
To evaluate (c ￮ d)(x), substitute x = d(x) into c(x)
c(x² + 5x)
= 4(x² + 5x) - 2
= 4x² + 20x - 2
35+15= 50 = 1 hour
50 + 15 =65 = 2hours
65 + 15 = 80 = 3 hours
80 + 15 = 95 = 4 HOURS
hope this helps :D
