I'm stuck on b, I've tried many methods but nothing seems to work (please help this is due in 3 hours)​

In the equations, a and b represent the price per night for a room in hotel a and hotel b, respectively, w weeks after september 1 last autumn. what was the price per night in hotel a when it was equal to the price per night in hotel b? a = 240 − 20w b = 320 − 30w

Consider a graph for the equation y= -3x+4. what is the y intercept? a) 4 b) -4 c) 3 d) -3

The number of potato chips in a bag is normally distributed with a mean of 71 and a standard deviation of 2. approximately what percent of bags contain between 69 and 73 potato chips? approximately 68% approximately 71% approximately 95% approximately 99.7%