exam Maths Puzzle Numerical Ability

I am trying to solve these equations by substitution or elimination amd then I have to interpret the result. Each time I do it, my solution comes out to 0. Can someone help me understand this?

2x+4y=10
3x+6y=12

Read Solution (Total 0)

exam Other Question

cashews sell for $5 per pound and peanuts sell for $2 per pound. How many pounds of each would you use to make 21 pounds of a mixture that sells for $3.00 per pound? john traveled 40 mph to his friends house
on the return trip back home he traveled 45 mph
It took him 4hrs round trip
Question: What was the total distance traveled?

Thank you