Write an equivalent expression by combining like terms when -4(3s) + 2(-t)= S=1/2 t= -3

Question

I really need help with 7th grade math and I'm stuck on this problem 

Answer 1

-4(3s)+ 2(-t)= s = 1/2t = -3

you may have miscopied a symbol or run together a couple problems

let's say you meant + when you typed = and left out some parthentheses

then

-4(3s)+2(-t)+s +(1/2)t + -3

= -12s-2t+s+.5t -3

= -11s-1.5t - 3