Question 241466
Solve using the substitution method.  First, solve one equation for one variable.

s + t = - 4,
s - t = 2
 
first we need to get single a single variable on one side of the equation, which is simpler in the second one.
subtract s from both sides and we get -t = 2-s
the we have to reverse the signs t = -2 + s so we have a positive value of T to substitue into the first equation. now we replace T in the first equation with -2+s
S + (-2 + S) = -4
-2 + 2s = -4
now we add 2 to each side to eliminate it single out the variable on the left side of the equation. (-2+2) + 2s = (-4+2)
2s = -2
now divide both sides by 2 to single out the variable on the left side of the equation.  2s/2 = -2/2
s = -1     Now that we haw a value for s we can check our work by substituting it into the original equations to see if it is true.
-1 + t = -4
t = -3
-1 + -3 = -4 True

S - T = 2
-1 - -3 = 2
-1 + 3 = 2 True
Hope this helps.