3/8(z+11)=y solve for z in the literal equation

On an airplane there are two seats on the left side and three seats on the right side there are 90 seats o the right side of the plane

What is the solution to this system of equations? y= 2x - 3.5 x - 2y = -14

Due to bad planning, two of the local schools have their annual plays on the same weekend. while 457 people attend one, and 372 attend the other, only 104 people were able to attend both. how many people went to at least one play?