Write an equation of the line with a slope of 23and y-intercept of −8.

If we have a y intercept of -8, that means that the point falls on the y-axis, therefore x = 0. So, we have a point (0, -8) and we have a slope m = 23.

y = mx + b

y = 23x + b

Now, we can plug in the point values x = 0, y = -8

-8 = 0 + b

b = -8

If we plug b back into our original formula, we get:

y = 23x - 8

v: l•w•h÷2.

v: 20•6•8 ÷2

v: 960÷2

v: 480