John can finish a paper route in 4 hours, and Andrew
can finish the same paper route in 7 hours. If they work together,
how long would it take them to finish the paper route?

in one hour, John does 1/5 of the route and Andrew does 1/7

Together, they do 1/x of the whole route, x being unknown.

(1/5)+(1/7)=(1/x) Multiply everything by 35x, the common denominator

7x+5x+35

12x=35

x=35/12 or 2 11/12 hours, or 2h55m

Step-by-step explanation:

for ex: the reciprocal of 3/4 is 4/3. it is the opposite.

reciprocal definition:

a mathematical expression or function so related to another that their product is one; the quantity obtained by dividing the number one by a given quantity.

c.35

step-by-step explanation:

8+13=21

21+8=29

29+6=35