Take out the 3 , to make the vertex form easier;)
Answer:
24
Step-by-step explanation:
f(x)=5x^2-7x
substitute x to 3
f(3)=5(3)^2-7(3)
f(3)=5(9)-21
f(3)=45-21
f(3)=24
Answer:
x = -2 or x=-5
Step-by-step explanation:
sqrt(x+6)-4 = x
sqrt(x+6) = x+4
square both sides
x+6 = x²+8x+16
x²+7x+10 = 0
(x+2)(x+5) = 0
x = -2 or x=-5
Substitute in original equation
x=-2 +/- sqrt(-2+6)-4 = 2-4 = -2 checks
x=-5 +/- sqrt(-5+6)-4 = -1-4 = -5 checks