Find the value of x that solves the system shown below.
y = 5x
2x - y = 18

Each month, a shopkeeper spends 5x + 14 dollars on rent and electricity. if he spends 3x−5 dollars on rent, how much does he spend on electricity? for which value(s) of x is the amount the shopkeeper spends on electricity less than $100? explain how you found the value(s).

The water level in the aquarium's shark tank is always greater than 25 feet. if the water level decreases by 6 feet during cleaning, what was the water level before the cleaners took out any water?

Apainting measures 2.4 feet from left to right. it's hung in the center of a rectangular wall measuring 20 feet from left to right. what is the distance between the right edge of the painting at the right edge of the wall?