Irene R. answered • 04/04/20
BS in Mechanical Engineering and Certified math teacher for 13 years
You can solve these two equations using elimination.
While there is more than one way to complete the elimination of one variable, we could start by multiplying the first equation by 2 and the second equation by -3 to eliminate the x variable and solve for y:
-3x - 7 y = -12 becomes -6x - 14y = -24
-2x - 3y = -3 becomes 6x + 9y = 9
Now combine these equations:
-6 x - 14 y = -24
6 x + 9 y = 9
-5y = -15
y = 3
Then substitute 3 for y in either original equation to determine the value of x. Let's use the second original equation:
-2x - 3y = -3
-2x - 3•3 = -3
-2x - 9 = -3
-2x - 9 + 9 = -3 + 9
-2x = 6
-2x/-2 = 6/-2
x = -3
The solution for these two equations is x = -3 and y = 3
