Hello can anyone help me with my algebra i'm behind

X+ y = 5 ; x - y =3 solve using linear combination

Seattle, washington is known for being rainy. one day last month, 8 inches of rain fell in 1 1/2 hours. what us the rate of the rainfall expressed in ft per plzzz write a proportion i will give you 100 points

Abook store is having a 30 perscent off sale. diary of the wimpy kid books are now 6.30 dollars each what was the original price of the books