Question

Solve 1/3x^2 + 11x - 75 < 105

a. -45 < x < 12
b. -5 < x < 12
c. x < -45 or x > 12

Answer 1

⅓x² +11x-75<105
⅓x² +11x-75-105<0
⅓x² +11x -180<0
x² +33x - 540<0
(x+45)(x-12)<0
(x-12)<0 or (x+45)>0
x<12 or x >-45
answer is A