I see your last line is : c(x) = 0.9(x^2-10)^2 + 101.1
Let y = x^2, then c(y) = 0.9(y-10)^2 + 101.1
Apparently, c(y) is a parabola, min is 101.1 when y = 10, max is infinity
So let x^2 = 10 -> x = sqrt(10) or -sqrt(10), min is 101.1, max is infinity
Wouldn't it be -1 (minus one)? 12 - 1 = 11 and 9 - 1 = 8.
Answer:
Step-by-step explanation:
9x - 4 + 5x + 16 = 180
14x + 12 = 180
14x = 168
x = 12
The answer should be the second one y=37
we have

Complete the square. Remember to balance the equation by adding the same constants to each side



Rewrite as perfect squares

remember that

Square root both sides





Simplify



therefore
<u>the answer is</u>

