Which pair of lines are perpendicular?
a. x - y = 7 and y = x + 3
b. y = -4x + 1 and 8x + 2y = -10
c. y = -8 and y = 2
d. x = 4 and y = -1

What is the slope of the line that passes through the points (–9, 2) and (0, 4)? the slope of the line is

(30 points). the population of a city is 45,000 and decreases 2% each year. if the trend continues, what will the population be aer 15 yrs

Jake volunteers to out his younger brother's basketball team in his free time. one of his tasks is to ensure that all the basketballs have enough air in them. given that a properly inflated basketball measures 8.8 inches across, what is the total volume of air inside six of jake’s basketballs? assume that the wall of each ball is infinitely thin.