How do you solve #6y - 8 = 12 + 10y#?

1 Answer
Nov 1, 2015

Expanded explanation

Explanation:

#color(red)("Objective is to have y, on its own, on one side of the = and everything else on the other side.")#

Brackets are used to show previous part to help make things clearer about what is happening.

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#color(blue)("Add 8 to both sides to remove it from the left.")#

#(6y-8) + color(red)(8) = (12 + 10y) + color(red)(8)#

#6y -8 + 8 = 12 +8 + 10y#

#6y +0 = 20 + 10y#

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#color(blue)("Subtract 10y from both sides to remove it from the right.")#

#(6y) - color(red)(10y) = (20+10y)-color(red)(10y)#

#6y - color(red)(10y) = 20+10y-color(red)(10y)#

#-4y = 20#

We need the y part to be positive so multiply both sides by negative 1

# color(red)(-1) times (-4y) = color(red)(-1) times (20)#

#4y =-20#

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#color(blue)("Divide both sides by 4 so that the 4 in front of 4y becomes 1. As 1 times anything is itself.")#

#color(red)(1/4) times (4y) = color(red)(1/4) times (-20)#

#1 times y = (-20)/4#

#y= - 5#