Someone please help me with this ASAP

If x + 10 = 70, what is x? a. 40 b. 50 c. 60 d. 70 e. 80

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

Clarence wants to buy a new car. he finds an ad for a car that costs 27,200 dollars. suppose his local sales tax is 7%. -how much would he have to pay? -what is the cost of the car including tax? -if clarence has 29,864 saved, can he pay cash to buy the car?