Question

Solve for x. Write the smaller solution first, and the larger solution second. 3x^2−9x−12=0

Answer 1

Smaller x = -1

Larger x = 4

Explanation:

Answer 2

x = -1 and x = 4

Explanation:

`3x^2-9x-12=0\qquad\text{divide both sides by 3}\\\\(3x^2)/(3)-(9x)/(3)-(12)/(3)=(0)/(3)\\\\x^2-3x-4=0\\\\x^2+x-4x-4=0\\\\x(x+1)-4(x+1)=0\\\\(x+1)(x-4)=0\iff x+1=0\ \vee\ x-4=0\\\\x+1=0\qquad\text{subtract 1 from both sides}\\x=-1\\\\x-4=0\qquad\text{add 4 to both sides}\\x=4`