SOLUTION: How would I make the equation f(x)=[-7/80](x-0)(x-40), which is in intercept form, into standard form and then into vertex form? ([-7/80] is a fraction)

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: How would I make the equation f(x)=[-7/80](x-0)(x-40), which is in intercept form, into standard form and then into vertex form? ([-7/80] is a fraction)      Log On


   

Question 1101646: How would I make the equation f(x)=[-7/80](x-0)(x-40), which is in intercept form, into standard form and then into vertex form? ([-7/80] is a fraction)
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29=%28-7%2F80%29%28x-0%29%28x-40%29
f%28x%29=-%287%2F80%29%28x%5E2-40x%29
f%28x%29=-7x%5E2%2F80%2B%287%2F2%29x
highlight%28f%28x%29=-%287%2F80%29x%5E2%2B%287%2F2%29x%29

-

f%28x%29=-%287%2F80%29%28x%5E2-40x%2B%2840%2F2%29%5E2-%2840%2F2%29%5E2%29------completing the square
-%287%2F80%29%28x%5E2-40x%2B20%5E2-20%5E2%29
-%287%2F80%29%28%28x-20%29%5E2-400%29
-%287%2F80%29%28x-20%29%5E2%2B%287%2A400%2F80%29
highlight%28f%28x%29=-%287%2F80%29%28x-20%29%5E2%2B35%29