c) mn=-2 d)
c) 3m+n=9 2m-5n = -11 n=9-3m 2m-5(9-3m)=-11 n=9-3m 2m-45+15m=-11 n=9-3m 17m=-11+45 n=9-3m 17m=34 n=9-3m m=34/17 n=9-3m m=2 n=9-6 m=2 n=3 m=2 -------------------- d) 4a-2=b 3a+7b=1,5 b=4a-2 3a+7(4a-2)=1,5 b=4a-2 3a+28a-14=1,5 b=4a-2 31a=1,5+14 b=4a-2 31a=15,5 b=4a-2 a=½ b=4*½-2 a=½ b=0 a=½ --------------- e) 5x=4-2y 4x+y=3 5x=4-2y y=3-4x 5x=4-2(3-4x) y=3-4x 5x=4-6+8x y=3-4x 5x-8x=-2 y=3-4x -3x=-2 y=3-4x x=2/3 y=3-4*2/3 x=2/3 y=1/3 -------------- f) 6x-3y=9 x+5y= -9,5 6x-3y=9 x=-9,5-5y 6(-9,5-5y)-3y=9 x=-9,5-5y -57-30y-3y=9 x=-9,5-5y -33y=9+57 x=-9,5-5y -33y=66 x=-9,5-5y y=-2 x=-9,5-5(-2) y=-2 x=½
c) {3m+n=9 {2m-5n = -11 {n=9-3m {2m-5n=-11 {n=9-3m {2m-5(9-3m)=-11 {n=9-3m {2m-45+15m=-11 {n=9-3m {17m=34 / :17 {n=9-3m {m=2 {n=9-3*2 {m=2 {n=3 {m=2 d) {4a-2=b {3a+7b=1,5 {b=4a-2 {3a+7(4a-2)=1,5 {b=4a-2 {3a+28a-14=1,5 {b=4a-2 {31a=15,5 /:31 {b=4a-2 {a=0,5 {b=4*0,5-2 {a=0,5 {b=0 {a=0,5 Sorry ale nie wiem naprawdę jak ostatnie przykłady...
