Three times a number plus 12 minus 5 times the same number is 22. what is the number?

Which number produces a rationale number when multiplied by 1/5

Find the slope and the y-intercept if there's one and the equation of the line given these two points( 3, 2) and( 3, -4)

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. when the check comes, it says they also need to pay $3.99 in sales tax. what percentage of the subtotal is the sales tax