Ask Question
29 September, 08:24

Solve the equation.

x2 - x - 12 = 0

A) x = 4

B) x = - 3

C) x = - 3 or x = 4

D) x = - 4 or x = 3

+3
Answers (1)
  1. 29 September, 08:48
    0
    C

    Step-by-step explanation:

    In this technique, if we have to factorise an expression like ax2+bx+c, we need to think of 2 numbers such that:

    N1⋅N2=a⋅c=1⋅-12=-12

    AND

    N1+N2=b=-1

    After trying out a few numbers we get N1=3 and N2=-4

    3⋅-4=-12, and 3 + (-4) = -1

    x2-x-12=x2-4x+3x-12

    x (x-4) + 3 (x-4) = 0

    (x+3) (x-4) = 0

    Now we equate the factors to zero.

    x+3=0, x=-3

    x-4=0, x=4
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “Solve the equation. x2 - x - 12 = 0 A) x = 4 B) x = - 3 C) x = - 3 or x = 4 D) x = - 4 or x = 3 ...” in 📗 Mathematics if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers