5x -9y = 17 .......equation(1)
2x - 7y = 0 ........equation(2)
from equation(2) above, make x the subject of the formular
x =7y/2.........equation(3)
substitute for x in equation(1) above
5(7y/2) - 9y =17
(35y/2) - 9y = 17
(35y - 18y)/2 = 17
35y - 18y = 17*2
17y = 34
y = 34/17
y = 2
substitute for y in equation(3)
x = 7y/2
x =7*2/2
x = 7, y = 2