rozwiąż układ równań: a) 2 ( x+y ) - (x-y) = 4 3 (x - 2y) + 4 (x+y)= 5 b) 4 (x+ 2y) - 3(x-y) = 42 2(y-x) +3 (x-y) = -6 c) 3 (x+y)- 2 (x- 2y ) =5 2(x + 2) - 4(y+1)= -8 Prosze pomóżcie ... ;)

Krycha128

2 ( x+y ) - (x-y) = 4 3 (x - 2y) + 4 (x+y)= 5 2x+2y - x +y = 4 3x - 6y + 4x +4y = 5 x + 3y = 4 7x - 2y = 5 x = 4 - 3y 7(4-3y) - 2y = 5 28 - 23y = 5 - 23 y = - 23 y = 1 x = 4 - 3 x 1 x = 1 y=1 x=1 ____________________________ 4 (x+ 2y) - 3(x-y) = 42 2(y-x) +3 (x-y) = -6 4x + 8y - 3x + 3y = 42 2y - 2x +3x - 3y = -6 x + 11y = 42 x - y = -6 /x(-1) x + 11y = 42 -x +y = 6 12 y = 48 y = 4 x = -2 y = 4 ______________________ 3 (x+y)- 2 (x- 2y ) =5 2(x + 2) - 4(y+1)= -8 3x + 3y - 2x + 4y = 5 2x + 4 - 4y - 4 = -8 x + 7y = 5 2x - 4y = -8 x = 5 - 7y 2(5 - 7y) - 4y = -8 10 - 14 y - 4 y = -8 10 - 18 y = -8 -18y = -18 y=1 x = 5 - 7 x = -2 x=-2 y=1

BOSKI0094

2(x+y) -(x-y) = 4 3(x-2y) +4(x+y) =5 2x+2y-x+y=4 3x-6y+4x+4y=5 x+3y=4 7x-2y=5 x=-3y+4 7x-2y=5 x=-3y+4 7(-3y+4) - 2y=5 x=-3y+4 -21y+28-2y=5 x=-3y+4 -23y=-23 | /(-23) x=-3y+4 y=1 x=-3*1 +4 y=1 x=1 y=1

ashlusx333

a) 2 ( x+y ) - (x-y) = 4 3 (x - 2y) + 4 (x+y)= 5 2x+2y-x+y=4 3x-6y+4x+4y=5 x+3y=4 /*(-7) 7x-2y=5 -7x-21y=-28 7x-2y=5 __________ -23y=-23 y=1 x+3*1=4 x+3=4 x=1 y=1 b) 4 (x+ 2y) - 3(x-y) = 42 2(y-x) +3 (x-y) = -6 4x+8y-3x+y=42 2y-2x+3x-3y=-6 x+9y=42 x-y=-6 -x-9y=-42 x-y=-6 ________ -10y=-48 y=4,8 x-4,8=-6 x=-1,2 x=-1,2 y=4,8 c) 3 (x+y)- 2 (x- 2y ) =5 2(x + 2) - 4(y+1)= -8 3x+3y-2x+4y=5 2x+4-4y-4=-8 x+7y=5 /*(-2) 2x-4y=-8 -2x-14y=-10 2x-4y=-8 __________ -18y=-18 y=1 x+7*1=5 x+7=5 x=-2 x=-2 y=1