Rozwiażcie mi te uklady rownań prosze!!:-* potrzebuje na zaraz!! a)7y+12=2x-5 12y+7x-18=21 b)2(c+d)=1 c-d=c+d c)p+u-1=0 2p+u=0

a) 7y+12=2x-5 12y+7x-18=21 7y - 2x = -17 /*7 12y + 7x = 39 /*2 49y - 14x = -119 24y + 14x = 78 73y = -41 y = -41/73 2x = 17 + 7*-41/73 2x = 20 + 68/73 x = 10 + 68/146 b) 2(c+d)=1 c-d=c+d c+d= 0,5 0 = 2d d = 0 c = 0,5 c) p+u-1=0 2p+u=0 u = 1 - p u = -2p -2p = 1 - p -p = 1 p = -1 u = 1 + 1 u = 2

b) {2(c+d)=1 { c-d=c+d {2c+2d=1 { c-c-d-d=0 {2c+2d=1 { -2d=0 {2c=1/:2 c=½ d=0 2c+2d=1 1+0=1 c) {p+u-1=0 {2p+u=0 {p+u=1/×(-1) {2p+u=0 {-p-u=-1 {2p+u=0 p=-1 2p+u=0 u=-2p u=-2/×(-1) u=2