What equation is the equation of the line that passes through (-10,8) and (5,5)

The equation of the line is given by

y = mx + c

where m is the gradient of the line
c is where the line cuts the y-axis
x & y represent coordinates on the line.

The gradient m can be obtained as follows:

m = (5 - 8) / (5 - - 10) = (-3) / (15) = - 1/5

To obtain c, we use any known coordinate on the line and substitute it as well as the gradient in the general equation for the line.

Taking coordinates (5,5)

5 = (- 1/5)(5) + c

5 = - 1 + c

c = 6

Hence, the equation for this line is

y = -x/5 + 6

The number is 80 because every number is multiplied by 2