Question 183802
Problem 1
First eliminate the parentheses by distribution
{{{4a-(4)(3)= 3-a-5}}}
remember that a - sign outside a ( stands for -1 so you need to multiply everything inside the parentheses by -1
simplify
{{{4a-12=-a-2}}}
Add 12 to both sides
{{{4a-12+12=-a-2+12}}}
{{{4a=-a+10}}}
Add a to both sides
{{{4a+a=-a+a+10}}}
{{{5a=10}}}
Divide both sides by 5
{{{5a/5=10/5}}}
{{{a=2}}}

Problem 2 is similar
{{{3z=2z-2*3+9}}}
{{{3z=2z-6+9}}}
{{{3z=2z+3}}}
Subtract 2z from both sides
{{{3z-2z=2z-2z+3}}}
{{{z=3}}}

Problem 3 has the - sign like problem 1. You should be able to follow the same steps