The length of a rectangle is the sum of the width and 1. The area of the rectangle is 72 units. What is the length in units of the rectangle

L = 9

Step-by-step explanation:

Translating this into symbols, we get L = W + 1 and A = 72 = W * L.

Substituting W + 1 for L in the latter equation, we get:

72 = W(W + 1), or:

W^2 + 1W - 72 = 0

This factors into (W + 9)(W - 8) = 0, so that W must be either -9 or +8.

Since W represents width, a physical measurement, we eliminate the negative result and conclude that W = 8 units.  Then L = W + 1 = 9 units.

Note that (8)(9) = 72, as we already know.

c

step-by-step explanation:

delaney would like to make a 5lb nut mixture that is 60% peanuts and 40% almonds.

she has several pounds of peanuts and several pounds of a mixture that is 20% peanuts and 80% almonds.

let 'p' represent the number of pounds of peanuts needed to make the new mixture, and  

let 'm' represent the number of pounds of the 80% almond-20% peanut mixture.

:

p + m = 5

therefore

m = (5-p)

write an equation based on the percent of peanuts

1p + .2m = .6(5)

replace m with (5-p)

p + .2(5-p) = .6(5)

p + 1 - .2p = 3

p - .2p = 3 - 1

.8p = 2

p = 2/.8

p = 2.5 lbs of peanuts required

then

5 - 2.5 = 2.5 lbs of the peanut/almond mixture required

:

a) what is the system that models this situation?

p + m = 5

1p + .2m = .6(5)