First you would do parenthesis according to the PEMDAS(Parenthesis, Exponents, Multiply, Divide, Add, Subtract) Rule
4 -2(-5a -10) = 30
4 + 10a + 20 = 30
Now you need to add 4 and 20 because they are on the same side
24 + 10a = 30
Now subtract 24 on both sides
24 + 10a = 30
-24. -24
10a = 6
Last divide 10 from both sides
10a/10. = 6/10
a= 6/10
Last simplify (optional but recommended)
a = 3/5 or 0.6
Hope this helped :)
A = 0.6
