Ron's recycle shop had an old paper-shredding machine. business was good, so he bought a new paper-shredding machine. the old machine could shred a truckload of paper in 4 hours. the new machine could shred the same truckload in 2 hours. how long will it take to shred the same truckload of paper if ron runs both shredders at the same time?

1 hour 20 minutes

Step-by-step explanation:

Given : The old machine could shred a truckload of paper in 4 hours.

Rate of work done by old machine =

The new machine could shred the same truckload in 2 hours.

Rate of work done by new machine =

Let 't' be the time taken by both of them working together , then we have the following equation:-

Since 1 hour = 60 minutes

Then,

Hence, it will take 1 hour 20 minutes to shred the same truckload of paper if Ron runs both shredders at the same time.

b

step-by-step explanation:

the equation of a line in point- slope form is

y - b = m(x - a)

where m is the slope and (a, b) a point on the line

calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (0, 4) and (x₂, y₂ ) = (3, - 5) ← 2 points on the line

m = = = - 3

with m = - 3 and (a, b) = (3, - 5), then

y - (- 5) = - 3(x - 3), that is

y + 5 = - 3(x - 3) → b