What is an approximate x-value for the equation y = –3x2 + 16 when y = 8?

1.63, -1.63

Step-by-step explanation:

y= -3x^2+16

if y is 8, then substitute that into the equation and solve for x

8=-3x^2+16

bring the variable and the constant to the other side

3x^2-8=0

factor 3 out (its ok if 8/3 isn't whole; do this to make the coefficient of x go)

x^2-8/3=0

This formula is recognizable. a^2-b^2 factors out to (a-b)(a+b)

a is x, b is

(x-)(x+)=0

so the appx x values for when y is 8 is the decimal form of and -

which is (keep in mind, i rounded this to the nearest 100th): 1.63 and -1.63

step-by-step explanation: