How do you factor the expression #x^2 − 3x − 88#?

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Answer 1 · 2016-03-16T12:42:54

#(x + 8 ) (x-11)# is the factorised form of the expression.

#x^2 - 3x -88#

We can Split the Middle Term of this expression to factorise it.

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

#N_1*N_2 = a*c = 1*-88 = -88#

AND

#N_1 +N_2 = b = -3#

After trying out a few numbers we get #N_1 = -11# and #N_2 =8#

#8*(-11) = -88#, and #8+(-11)= -3#

#x^2 -color(blue)( 3x) -88 =x^2 color(blue)(- 11x +8x) -88 #

#=x(x-11) + 8 (x-11)#

#=(x + 8 ) (x-11)#