Question 369544
 2s - 13t = 120
-14s + 91t= -840
 How to solve by substitution or elimination
--------------
Multiply the 1st eqn by 7
 14s - 91t = 840
-14s + 91t= -840
The 2nd eqn is -1 times the first.
--> dependent
infinite # of solutions.
In essence, 2 versions of the same equation