Answer:
x = 12
Explanation:
to solve for x we want to get it by itself
4x + 3 = 51 < subtract 3 from both sides is the first step to get x alone
-3 -3
4x = 48 < now we divide both sides by 4 to get rid of the 4x, as x is being multiplied by 4
4x/4 = x
48/4 = 12
x = 12 is our answer, you can check by plugging in the value for x into the original equation, but its not necessary