Klaus was replacing the roof on his house. he used 420 nails to attach al the pieces of wood. each piece of wood needed 7 nails to hold it in place. he used 40 pieces of wood. how many pieces were left?

There were 20 pieces of wood left.

Work:

420 ÷ 7 = 60

60 - 40 = 20

Your answer is 20.

Hope this helps!

2.

according to newton’s cannonball model, what happens if the cannonball's velocity is enough to overpower the pull of earth’s gravitystep-by-step explanation:

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)