mike, dave and john worked for a total of 56 hours. Dave worked 6 more than 4 times as many hours as mike. John worked 6 less than 3 times as many hours as Mike. How long did Dave work?

mike dave and john worked for a total of 56 hours Dave worked 6 more than 4 times as many hours as mike John worked 6 less than 3 times as many hours as Mike Ho class=

Respuesta :

Answer:

1. Dave worked for 34 hours.

2. Perimeter of the rectangle is 172 cm.

Step-by-step explanation:

1. Determination of the hours Dave worked.

Let D represent Dave.

Let M represent Mike.

Let J represent John.

Tota time worked by Dave, Mike and John is 56 hours. This can be written as:

D + M + J = 56 ..... (1)

Dave worked 6 more than 4 times as many hours as Mike. This can written as:

D = 6 + 4M .....(2)

John worked 6 less than 3 times as many hours as Mike. This can be written as:

J = 3M – 6 ........ (3)

Substituting the value of F and J into equation 1, we have:

D + M + J = 56

D = 6 + 4M

J = 3M – 6

6 + 4M + M + 3M – 6 = 56

6 – 6 + 4M + M + 3M = 56

8M = 56

Divide both side by 8

M = 56/8

M = 7

Substitute the value of M into equation (2) to obtain the value of D.

D = 6 + 4M

M = 7

D = 6 + 4(7)

D = 6 + 28

D = 34

Therefore, Dave worked for 34 hours .

2. Determination of the perimeter.

Length (L) = 64 cm

Width (W) = 22 cm

Perimeter (P) =?

P = 2(L + W)

P = 2 (64 + 22)

P = 2 (86)

P = 172 cm

Therefore, the perimeter of the rectangle is 172 cm