How do you solve #3x ^ { 2} - 6x - 72= 0#?
1 Answer
Apr 17, 2018
Explanation:
#"take out a "color(blue)"common factor "3#
#rArr3(x^2-2x-24)=0#
#"to factor the quadratic"#
#"the factors of - 24 which sum to - 2 are - 6 and + 4"#
#rArr3(x-6)(x+4)=0#
#"equate each of the factors to zero and solve for x"#
#x-6=0rArrx=6#
#x+4=0rArrx=-4#