7/10-1/2 in simple form. so the two fractions have different denominators so you need to multiply both denominators 10x2 = 20 so both fractions have 20 on the bottom so they are like this now: 7/20-1/20= 6/20 simplify by 2: 6/20 divide by 2/2 =3/10. 3/10 is your answer
Probably y = 8x. 56 = 8(7), so that works. Without more data, I couldn't say if it could be something else, so that's what I go with.
The solution is (-2,4) she right both have the same solution because if you solve both of them you will get (-2,4)