I am having a hard time with n-1 x 5x2/3=3/4

Part a : solve -vp + 40 < 65 for v part b : solve 7w - 3r = 15 for r show your work .

Cal's go cart has a gas tank with the dimensions shown below. he uses a gas can that holds 11 gallon of gas, to fill the go cart tank. 11 gallon = 231 inches^3 how many full gas cans will it take to fill the go cart's gas tank?

y=2x−1 5x−4y=1 is (1,1)(1,1) a solution of the system?