Please answer both of them questions please no links or you will be reported

Ifurniture stores having a weekend sale and is offering 20% discount on patio chairs and table the sales tax on furniture is 6.25 using function composition how can you represent the total amount a that you would need to pay for this furniture that cost x dollars

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

15 and 14.7 are 1 apart, so 15 – 14.7 must be 1.