Would any one like to help me on this question?

Line cd passes through points c(1, 3) and d(4, –3). if the equation of the line is written in slope-intercept form, y = mx + b, what is the value of b? –5 –2 1 5

What is the slope simplify your answer and write it as a proper fraction, improper fraction, or integer

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