What value of y satisfies the equation 3y + 6 = 21?
A 5
B 7
C 9
D 12
To solve the equation 3y + 6 = 21, we need to isolate the variable y by undoing the operations that have been done to it.
Step 1: Start by subtracting 6 from both sides of the equation:
3y + 6 - 6 = 21 - 6
This simplifies to:
3y = 15
Step 2: Divide both sides of the equation by 3 to solve for y:
3y/3 = 15/3
This simplifies to:
y = 5
Therefore, the value of y that satisfies the equation 3y + 6 = 21 is y = 5.