Răspuns:
a)x+y=3
x-y=7
x=3
x=7
2x=10
x=5
5+y=3
y=3-5
y=-2
c)x+y=7|*-1
-4x+y=-3
-x-y=7
-4x+y=-3
x=7
-4x=-3
-3x=4
x=4/-3
4/3+y=7
1.(3)+y=7
y=7-1.(3)
y=5.67
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e)3x+2y=10|*8
7x-8y=-2|*2
24x+16y=80
14x-16y=-4
24x=80
14x=-4
38x=76
x=76/38
x=2
6+2y=10
2y=4
y=2
x=y=2