We are given the following expression:
[tex]c-20+(4c)[/tex]we are asked to determine the value of the expression when c = 30. To that, we replace the value of c in the expression for 30, like this:
[tex]30-20+(4\times30)[/tex]Now we solve the operation in the parenthesis:
[tex]30-20+120[/tex]Now we solve the subtraction:
[tex]10+120[/tex]Now we solve the last operation:
[tex]130[/tex]Therefore, the value of the expression when c = 30 is 130
