Using the linear combination method, we can add 3x+7y=31 and -3x-2y=-1 together, which makes 5y=30.
Just divide both sides by 5, and your answer will be y = 6.
To solve for x, just substitute 6 in y in either equation and solve for x:
[tex] -3x-2(6)=-1\\ -3x-12=-1\\ -3x=11\\ x=-\frac{11}{3} =-3\frac{2}{3} [/tex]
In short, the correct answer is B. -3 2/3
