Question 256488
I'm not sure what you want to do here. Do you want to evaluate {{{3(x-5)}}} when {{{x^2=49}}} ?



If so, then solve {{{x^2=49}}} to get {{{x=7}}} or {{{x=-7}}} and then simply plug those values into {{{3(x-5)}}} to get {{{3(7-5)=3(2)=6}}} or {{{3(-7-5)=3(-12)=-36}}}