exam Maths Puzzle Numerical Ability

Would someone be able to help me with this problem?

x+5y=10
-2x-10y=-20
Solve by addition.

Read Solution (Total 0)

exam Other Question

Allen bought 21 stamps in 37-cent and 20-cent denominations. If the total cost of the stamps was $7.26, how many 37-cent stamps did Allen buy?
I am having trouble with another question for a homework assignment:
For the line 7x-4y =14, determine X intercept, Y intercept, and slope. Thank you so much