book Maths Puzzle Numerical Ability

i dont know how to do some of these problems

2y-4(y-5)+3(y+11)=6y

and

2x+3y=9

Read Solution (Total 0)

book Other Question

121 angle /and 5 angle. what is the remaining angle? In a medical certificate, by mistake a candidate gave his height as 25% more than normal. In the interview panel, he clarified that his height was 5 feet 5 inches. Find the percentage correction made by candidate from stated height to his actual height?