Derrick has a total of 9 nickels and quarters in his pocket. the total amount of money he has in coins is $1.45. how many nickels and how many quarters does derrick have? a. 3 nickels and 6 quarters b. 6 nickels and 3 quarters c. 4 nickels and 5 quarters d. 5 nickels and 4 quarters

Option C. 4 nickels and 5 quarters

Step-by-step explanation:

let the number of nickels = x, and the number of quarters = y

Derrick has a total of 9 nickels and quarters in his pocket

So, x + y = 9

∴ y = 9 - x ⇒(1)

1 nickel = 5 cent = $0.05

1 quarter = 25 cent = $0.25

The total amount of money he has in coins is $1.45

So, 0.05 x + 0.25 y = 1.45

Multiply the both sides by 100

∴ 5x + 25y = 145 ⇒(2)

Substitute with y from (1) at (2)

∴ 5x + 25(9-x) = 145

Solve for x

5x + 225 - 25x = 145

-20x = 145 - 225 = -80

x = -80/-20 = 4

Substitute with x at (1)

y = 9 - 4 = 5

So, The number of nickels = 4 , and the number of quarters = 5

The answer is option C. 4 nickels and 5 quarters

1.0

step-by-step explanation:

the answer would be d

straight away you can eliminate a and c because not all books contain a scientific skill because some may be fiction. c is also wrong because it saids that the only way children can learn is through books which is incorrect.

b is also wrong because reading can be a scientific skill but not always, therefore it is wrong which leaves you with d, the correct answer since it said that it can children learn.

hope this ! : 3