{ x+y=9 { x-y=3 __________ 2x = 12 x = 6 podstawiamy do pierwszego { x+y=9 6+y = 9 y = 3 {x+4y=11 /*(-2) {2x+5y=10 -2x-8 y= -22 2x+5y=10 ____________ -3y = -12 /:(-3) y = 4 podstawiamy tu: {x+4y=11 x + 4*4 = 11 x +16 = 11 x = -5
a) { x+y=9 / { x-y=3 / + { 2x = 12 /:2 { x + y = 9 { x = 6 { 6 + y = 9 {x = 6 {y = 9 - 6 {x = 6 {y = 3 b) {x+4y=11 /x(-2) {2x+5y=10 {-2x - 8y = -22 / {2x + 5y = 10 / + {- 3y = - 12 / : (-3) {x + 4y = 11 { y = 4 { x + 16 = 11 { y = 4 { x = -5
1] x+y=9/×(-1) x-y=3 -x-y=-9 x-y=3 -2y=-6 y=-6:-2 y=3 x+3=9 x=9-3 x=6 spr. 6+3=9 9=9 6-3=3 3=3 b] x+4=11/×(-2) 2x+5y=10 -2x-8y=-22 2x+5y=10 -3y=-12 y=-12:-3 y=4 x+4×4=11 x=11-16 x=-5 spr.-5+4×4=11 -5+16=11 11=11 2×-5+5×4=10 -10+20=10 10=10
