How do you solve #2x^2 + 18x = 20#?

1 Answer
Brandon T. · Rachel
May 16, 2017

#x=-10#
#x=1 #

Explanation:

In order to solve this you must factor it.
1. Subtract the 20 to the left side of the equation.

#2x^2+18x-20=0#

  1. Divide all by 2 in order to isolate the x^2

#(cancel(2)(x^2+9x-10))/cancel(2)=0/2#

  1. Factor.
    You must find 2 numbers that add to 9 and multiply to -10.

Those two factors would #10# and #-1#.

add them to #x# and set to 0

#(x+10)(x+ -1)=0#

#color(white)(0)x + 10 = 0## color(white)(0000)#and#color(white)(000)##x + -1 = 0#

  1. Solve.
    #x=-10#
    #x=1 #
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