Question

5x + 2y = 7 10x + 4y = 14

Answer 1

x and y on the left and right both equal 1

Answer 2

look at them 5x+2y=7
10x+4y=14

divide second euqtion by 2
5x+2y=7
5x+2y=7
they are same

the solution is any oint on the line 5x+2y=7
some points are
(1,1)
(0,3.5)
(1.4,0)
etc
infinitely many