Answer: A. 30. x=30/ 30=x *The answer should be the positive sign.*
Explanation:
subtraction property of equality is subtracting the same number from both sides of an equation does not change the equation.
a-c=b-c
addition property of equality is adding the same number to both sides of an equation does not change the equation.
a+c=b+c
subtract by 15 both sides of an equation.
x+15-15=45-15
simplify.
45-15=30
30+15=45
45-30=15
x=30 and 30=x
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