(a) the slope is 2 and y-intercept is 15
slope is the factor in front of x
y-intercept is obtained by setting x=0: y=2*0+15 = 15
(b) the rate of change (aka slope) is 2 baskets per hour. This means that every additional hour of picking there are 2 more baskets of berries than before. The initial amount is 15. This means that there were 15 baskets of berried picked before starting counting the hours.