Question

c) 4x - 2y =10
2x+3y=1


d) 4x - 2y=-2
3x + y=-9




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Answer 1

Răspuns:

c)

4x-2y=10

2x+3y=1   I×(-2)

___________

4x-2y=10

-4x-6y=-2

__________

 /    -8y=8=>y= -1

4x-2·(-1)=10

4x+2=10=>4x=10-2=>x=8:4=>x=2

d)

4x - 2y=-2

3x + y=-9   I×2

_________

4x-2y=-2

6x+2y=-18

_________

10x   /   = -20

x=-20:10=>x= -2

4·(-2)-2y=-2

-8-2y=-2

-2y=-2+8=>y=-6:2=>y= -3

Answer 2

c) 4x-2y=10 | •3
2x+3y=1 | •2
——————— +
16x/=32
x=2
4*2-2y=10
8-2y=10
-2y=10-8
-2y=2
-y=51
y=-1


d)4x-2y=-2
3x+y=-9 | •2
—————+
10x/=-20
x=-2
3*2+y=-9
6+y=-9
y=-15