Good morning! I am trying to help my nephew who because of seizures when he was younger has a hard time understanding math. I need step-by-step (written in words) on how to do two-step equations (distributive properties). 3(c+5)=12. 5(4d+8)=40.

Question

Good morning! I am trying to help my nephew who because of seizures when he was younger has a hard time understanding math. I need step-by-step (written in words) on how to do two-step equations (distributive properties).  3(c+5)=12.   5(4d+8)=40. 
-(2k-11)=7.   3/4(4x+8)=-12       -4(3x-2)=-32.   1/3(9c-36)=-9
Any help would be greatly appreciated!

Steve · Answer

step 1: remove the parentheses, by applying the distributive property
step2: collect all the variable stuff on one side, by adding/subtracting the constants
step3: divide by the coefficient to isolate the variable value

3(c+5) = 12
1:3c+15 = 12
2:3c = 12-15 = -3
3: c = -1

3/4 (4x+8) -12
3x+6 = -12
3x = -18
x = -6

and so on