Question

what is the value of ax^2 + bx +c at x= -b/a? solve clearly and smoothly

Answer 1

x = $\frac{-b}{a}$

ax² + bx + c
= a($\frac{-b}{a}$)² + b($\frac{-b}{a}$) + c
= a(b²/a²) + (-b²/a) + c
= b²/a - b²/a + c
= c

Hope it helps