How do you solve for x: #-3/4 x = 12#?

Question

1595 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-07-21T09:49:41

#x = -16#

There are a few ways of approaching the question, but they will all give the same answer.

Method 1. We can get rid of the denominator first, and then divide by -3 as a second step.

#(color(blue)(cancel4xx)-3)/cancel4x =color(blue)(4xx)12#

#(-3)/(color(red)(-3))x = 48/(color(red)(-3)#

#x = -16#

Method 2: multiply both sides by the reciprocal of #-3/4#

#-3/4x xx color(blue)(-4/3) = 12xxcolor(blue)(-4/3)#

#x = 16#

Method 3. Because we have an equation with one fraction o each side, we can cross-multiply,

#-3/4x =12/1#

#-3x = 48#

#x = -16#