Answer:
Explanation:
-12 = 6y + 18 – 9y
[Group like terms 6y and -9y]
-12 = (6y – 9y) + 18
[Simplify the expression]
-12 = -3y + 18
[Subtract 18 from both sides, subtraction property of equality, to isolate the variable and the value]
-12 = -3y + 18
–18 –18
-30 = -3y
[Divide by -3 from both sides, division property of equality, to get the variable y by itself]
-30 = -3y
÷(-3) ÷(-3)
10 = y
[Symmetric property of equality, if b = a, then a = b]
y = 10