f(x) = -7x2 + 9x + 9.

Question

Select the approximate values of x that are solutions to f(x) = 0, where
f(x) = -7x2 + 9x + 9.

Answer 1

First step is the set the polynomial equal to zero:    

 

 -7x²+9x+9=0

 

Second step is to use the quadratic formula: 

 

x=(-b+sqrt(b²-4ac))/(2a )   and   x=(-b-sqrt(b²-4ac))/(2a) 

 

This indicates that there will be two solutions.

Since the polynomial is in the form ax²+bx+c,  

 

a=-7

b=9

c=9

 

Third step is to substitute these values into the quadratic formulas and obtain the two solutions.