5x - 20y = 70
6x + 5y = -32 Here we can solve this systme by at least 4 methods: by summing/subtracting these equations, graphically, by substitution, and by using Cramer's Rule.
The method by substituion is when you express one variable in the terms of other from one equation and then insert it into the other . Let's do it with the second equation and express x for example:
6x + 5y = -32 => x = (-32 - 5y)/6 and insert this expression into the first one: -(5(32 + 5y)/6) - 20y = 70 => -160 - 25y/6 - 20y = 70 =>
-160 - 25y - 120y = 420 => -145y = 580 => y = -4. So we find the other variable. By inserting this value into the expression for x we find the other variable and thus solve the sustem: x = (-32 - 5*(-4))/6 = (-32 + 20)/6 = -12/6 = -2. So the answer is (-2 ; -4)
+4 
+259 
