3 roll 2 column matrix addition to 3 roll 3 column

Aboard 60 in. long is cut two parts so that the longer piece is 5 times the shorter. what are the length of the two pieces?

Taber invested money in an account where interest is compounded every year. he made no withdrawals or deposits. the function a(t)=525(1+0.05)^t represent the amount of money in the account after t years. how much money did taber origanally invested?

Solve the system of equations. 2x-2y=-4 and x+y=8. show work