Question

用加减消元法解方程组:

(1) (2) (3)
{2x+3y=-7 {4x-3y=14 {5x-3y=8
{3x+2y=7 {3x+4y=2 {3x+5y=-2

【三题，都要过程！】『求解答！』
急！

Answer 1

(1)3*①-2*②=5y=-35 --> y=-7; 2*①-3*②=-5x=-35 --> x=7.
(2)3*①-4*②=-25y=34 --> y=-34/25; 4*①+3*②=25x=62 --> x=62/25.
(3)3*①-5*②=-34y=34 --> y=-1; 5*①+3*②=34y=34 --> x=1