Question

solve:x/4+y/5=1,2x/9-y/9=-2

Answer 1

clean up your equations

x/4 + y/5 = 1 --times 20 --> 5x + 4y = 20
2x/9 - y/9 = -2 -----> 2x - y = -18
y = 2x+18
using substitution,
5x + 4(2x+18) = 20

carry on