a) 3x+2y+13 2x+y=11/*(-2) 3x+2=13 -4x-2y=-22 -x=9/-1 x=-9 3x+2y=13/*2 2x+y=11/*(-3) 6x+4y=26 -6x-3y=-33 y=7 b)5x+3y=0 -x-2y=7/*5 5x+3y=0 -5x-10y=35 -7y=35 y=-5 )5x+3y=0/*2 -x-2y=7/*3 10x+6y=0 -3x-6y=21 7x=21 x=3 c) 3u + 2v = 2/*(-5) 5u + 4v = 6/*3 -15u-10v=-10 15u+12v=18 2v=8/:2 v=4 3u + 2v = 2/*(-2) 5u + 4v = 6 -6u-4v=-4 5u+4v=6 -u=2/:(-1) u=-2
a) {3x + 2y=13 2x + y=11// razy(-2) {3x + 2y=13 -4x-2y=-22 +_______________ -x=-9 x=9 y=11-2x y=11-2 razy 9 y=11-18 y=-7 {x=9 y=-7 b){ 5x + 3y = 0 -x - 2y = 7 {5x + 3y = 0 -x - 2y=7// razy 5 {5x + 3y=0 -5x-10y=35 +___________ -7y=35 y=-5 -x=7+2y -x=7+(-10) -x=-3 x=3 {x=3 y=-5 c) { 3u + 2v = 2 // razy (-2) 5u + 4v = 6 {-6u -4v=-4 5u + 4v = 6 +_________ -u=2 u=-2 4v=6-5u 4v=6+10 4v=16 v=4 {u=-2 v=4
