How do you solve #-3( x + 4) + 15= 6- 4x#?

1 Answer
Mar 13, 2017

#x=3#

Explanation:

The first step is to distribute the bracket on the left side.

#rArr-3x-12+15=6-4x#

#rArr-3x+3=6-4x#

Collect terms in x on the left side and numeric values on the right side.

add 4x to both sides.

#-3x+4x+3=6cancel(-4x)cancel(+4x)#

#rArrx+3=6#

subtract 3 from both sides.

#xcancel(+3)cancel(-3)=6-3#

#rArrx=3#

#color(blue)"As a check"#

Substitute this value into the equation and if the left side equals the right side then it is the solution.

#"left side "=-3(3+4)+15=(-3xx7)+15#

#color(white)(left side)=-21+15=-6#

#"right side"=6-(4xx3)=6-12=-6#

#rArrx=3" is the solution"#