Subtract because it has to deal with the many signs
slope = - 
using the points on the line ( - 4, 5 ) and ( 1, - 4 )
slope = ( - 4 - 5 )/( 1 - ( - 4 )) = - 
P(blue marble)=2/6
p(yellow marble)=1/4
p(yellow&blue marble)=2/6+1/4=1/3
2 is a prime number for 14 and 24
Hope this helps!!