Question

If x+y=1, and x-y=1, then y =?

Answer 1

Hey there!!

x + y = 1 --------- ( 1 )

x - y = 1 ---------- ( 2 )

If we add both the equation, we get

2x = 2

x = 1

Now substitute this into any equation,

1 + y = 1

y = 0

Y = 0

Hope my answer helps!

Answer 2

We can solve these two equations as a system. Call them (A) and (B). Either substitution or elimination could be used.

(A) x + y = 1

(B) x - y = 1

By elimination (or linear combination), we add so that the y terms go to zero.

2x = 2. <----after adding

x = 1 <-----divide both sides by 2

With x = 1, we put that into our original equation. Let's go into (A)

x + y = 1

1 + y = 1

y = 0

Thus x = 1 and y = 0