Question

Use the quadratic model y = −4x2 − 3x + 4 to predict y if x equals 5.

Answer 1

y = -4x^2 - 3x + 4
x = 5

y = -4(5)^2 - 3(5) + 4

y = -4(25) - 15 + 4

y = -100 - 15 + 4

y = -114

Answer 2

Please, write -4x^2 (not 04x2).
Then the quadratic model is y = -4x^2 - 3x + 4.
Now substitutet 5 for x: y(5) = -4 (5)^2 - 3(5) + 4
Simplifying, y(5) = -4(25) - 15 + 4 = -100 - 11 = -111.