Im literally in tears this is so frustrating! brainliest answer a coin collector has $1.90 in dimes and nickels. she has seven more dimes than buckles. how many nickels does she have ?

d= dimes

n = nickels

d =n+7

n*.05+.1*d = 1.90

substitute d = n+7

.05n +.1 (n+7) = 1.9

distribute

.05n +.1n +.7 = 1.90

combine like terms

.15n +.7 = 1.9

subtract .7 from each side

.15n = 1.2

divide by .15

n=8

d=n+7

d=15

you have 8 nickels and 15 dimes

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)