Easy
Solve the pair of linear equations for x: 1x + 3y = 12 and 5x + -1y = -20.
Explanation
Explanation
Using the elimination method: multiply the first equation by -1 and the second by 3, then subtract to eliminate y. Solving gives x = -3 (and correspondingly y = 5). You can verify: 1(-3) + 3(5) = 12 ✓ and 5(-3) + -1(5) = -20 ✓.
PRO TIP
Re-check your working by substituting the answer back into the original question.