5(2a-2)=7(a+8)-27
5(2a-2)=7(a+8)-27 Use distributive property
10a-10 = 7a+56 - 27 Add 10 to both sides
10a = 7a + 56- 27 + 10 Subtract 7a from both sides
10-7a = 56-27+10 simplify
3a = 39 divide both sides by 3
a = 13
Its actually
10a-7a=56-27+10
3a=39
a=13