I need help with this question about the Pythagorean Theorem can anyone help me?

Let's eliminate the variable x.   to do this, mult. the 2nd eqn by   -2, obtaining  -2x - 4y = 8.   to this add the 1st equation: -2x - 4y = 8  2x - 3y = 13        -7y = 21.   div. both sides by -7, we get y = -3.to find y, subst. -3 for y in the 2nd eqn.   result:   x + 2(-3) = -4                                                                              x - 6 = -4                                                                              x = 2solution is (2, -3)