The points given in the table lie on a line. fund the slope of each line

For the first table
consider A(x1,y1)=A(0;3)  and B(x2;y2)=B(1;5)

the slope m= (y2-y1)/(x2-x1) = (5-3)/(1-0) = 2/1=2

for the second table 
consider again A(x1;y1)=A( 0;9)  and B(x2;y2)=B(2;4)

the slope m= (y2-y1)/(x2-x1)= (4-9)/(2-0)= -5/2= -2.5

4x 20 is 80 but if ther machine is broken then there is none you have to redo the test