The amount of time it takes p people to paint d doors varies directly with the number of doors and inversely with the number of
people. Four people can paint 10 doors in 2 hours. How many people will it take to paint 25 doors in 5 hours?

Step-by-step explanation:

time ∝ number of door 1

time . ∝ 1/number of people. 2

compare equation 1 and 2

time . ∝ number of door / number of people

put k as constant

time = k number of door / number of people. 3

time =2. people=4 door = 10

putting in equation 3

2 = k (10)/(4)

2×4/10 = k

8/10 =k

4/5 =k

putting in equation 3

time= 4/5 number of door / number of people

now time =5 door= 25 people=?

5=4/5 (5)/ (number of people)

number of people =4/5 ×25/5

number of people= 4

the answer is here: : )

:

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116