The first step in solving for a in the equation would be:
1.distribute -4 to a and -5, then:
2a-4a+20=10
Now the next steps in solving for a:
2.Add 2a and -4a :
-2a+20=10
3.Substract 20 to both sides
-2a+20-20=10-20
then:
-2a= -10
4.Finally, divide both sides by -2
[tex]\frac{-2a}{-2}=\frac{-10}{-2}=5[/tex]then, a=5