How do you solve #(x + 42 ) + 3x = 90#?

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Answer 1 · 2018-02-01T16:37:39

See a solution process below:

First, take the terms out of the parenthesis being careful to manage the signs of the individual terms correctly:

#x + 42 + 3x = 90#

Next, subtract #color(red)(42)# from each side of the equation to isolate the #x# term while keeping the equation balanced:

#x + 42 - color(red)(42) + 3x = 90 - color(red)(42)#

#x + 0 + 3x = 48#

#x + 3x = 48#

#1x + 3x = 48#

#(1 + 3)x = 48#

#4x = 48#

Now, divide each side of the equation by #color(red)(4)# to solve for #x# while keeping the equation balanced:

#(4x)/color(red)(4) = 48/color(red)(4)#

#(color(red)(cancel(color(black)(4)))x)/cancel(color(red)(4)) = 12#

#x = 12#