need help.....MATHS....arggghhhh

Read your textbook and follow the examples.

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

double eqn 1

2[2x-y=-4] becomes 4x-2y=-8

add doubled eqn 1 to eqn 2

[4x-2y=-8]+[x+2y=3]=(4x+x)+(-2y+2y)=(-8+3)

this becomes 5x+0y=-5 or 5x=-5

now divide [5x=-5] by 5 and x=-1

put this value of x into eqn 2 [x+2y=3] and this becomes
[-1+2y=3] rearrange and [2y=3+1=4 or 2y=4
divide this by 2 and y=2

so the solution by substitution and elimination is x=-1 and y=2

now check the solution x=-1 y=2

1) 2x-y=-4 becomes 2(-1)-2=-2-2=-4 ok
2) x+2y=3 becomes -1+2(2)=-1+4=3 ok

Rap