How do you factor #3x^2 +10x - 8#?
2 Answers
Explanation:
first multiply
then find two numbers that if we add or subtract we get
and the numbers are
then we place those numbers as follow :-
then we group them
now take the common factor out.
then group the numbers outside of the brackets
and that is the answer
Proper Solution:-
Explanation:
#"for a quadratic in "color(blue)"standard form"#
#•color(white)(x)ax^2+bx+c ;a!=0#
#"consider the factors of the product ac which sum to b"#
#3x^2+10x-8larrcolor(blue)"is in standard form"#
#"with "a=3,b=10" and "c=-8#
#"consider factors of "3xx-8=-24" which sum to + 10"#
#"the required factors are "+12" and "-2#
#color(blue)"split the middle term using these factors"#
#3x^2+12x-2x-8larrcolor(blue)"factor by grouping"#
#=color(red)(3x)(x+4)color(red)(-2)(x+4)#
#"take out the common factor "(x+4)#
#=(x+4)(color(red)(3x-2))#
#rArr3x^2+10x-8=(x+4)(3x-2)#