Question 31324
3x-16=5y & 33-5y=4x or 3x-5y=16 & -4x-5y=-33 multiplying the second equation by -1  we get 4x+5y=33 adding this to 3x-5y=16 we get 7x+0y=49 or 7x=49 or x=7

therefore 3(7)-16=5y or 21-16=5y or 5=5y or y=1

proof 33-5(1)=4(7) or 33-5=28 or 28=28