Question

using substitution or elimination solve this: x^2-y^2=15 and x+y=1

Answer 1

Notice that x^2 - y^2 is a difference of two squares. This means: x^2-y^2 = (x+y)*(x-y) = (1)*(x-y) = x-y = 15.

Therefore you have two equations and two unknowns:
1) x-y=15
2) x+y=1

Answer 2

can it still be solved?

Answer 3

can you continue the problem and use elimination?

Answer 4

or is this no solution?