A map says that Philadelphia and New York are 90 miles apart. If the 1 inch equals 10 miles, how a far apart are Philadelphia and New York on the map?
90 miles

9 inches

Step-by-step explanation:

Don't feel confused, just break this thing down.   So I know that 1 inch equals 10 miles on a map (before GPS we had to use those maps).  If 1 inch equals 10 miles, or you could say 1:10 or 1 to 10,  how many go with 90, or what times 10 equals 90? I know that 1 goes with 10 (multiply by 10) so 9 has to go with 90 because 9 times 10 equals 90.  

21

jk it's 20

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)