You have to distribute the 4 to the numbers in the parenthesese. So 4 times 3x which is 12x and 4 times 5 which is 20 so now you get 12x plus 20 equals 8. Now you have to subtract 20 from 8 which is -12 so now you have 12x=-12 now divide the 12 from x and 12 from -12 and so now you have x=-1
It isn't true at all it isn't a question even
<span>2x+3y=7
x-y=1
</span>2x+3y=7
x=1+y
2*(1+y)+3y=7
x=1+y
2+2y+3y=7
x=1+y
5y=5 |(:5)
x=1+y
y=1
x=2
CHECK:
2x+3y=7
x-y=1
2*2 + 3*1 = 7
x-y = 1
2-1 = 1