Step-by-step explanation:
7x-21 = 5x +15
7x-5x = 15 + 21
2x = 36
x = 36/2
x = 18
Answer:
x=18
Distribute 7 through the parentheses
7x-21=5(x+3)
Move the variable to the left -hand side and change its sign
7x-21-5x=15
Collect like terms
2x=15+21
divide both sides of the equation by 2
