Mary has a collection of nickels and quarters for a total value of 4.90.if she has 42 coins total how many of each kind are there

Let x be the number of nickels and y be the number of quarters.

Then, x + y = 42 --- (1)

It is given that total value = 4.90.

Therefore, 0.05x + 0.25y = 4.9 --- (2)

Multiply (1) by 0.25

0.25x + 0.25y = 10.5 --- (3)

Now, subtract (2) from (3), we get,

0.2x = 5.6

Divide both sides by 0.2.

x = 28

x + y = 42

y = 42 - x

= 42 - 28

= 14

Hence, Mary has 28 nickels and 14 quarters in total.

t = 3

step-by-step explanation:

put t = 3 in this expression :

(3²-1)(3²-2)(3² - 3)(3² - 4) = 8×7×6×5 = 56×30 = 1680

42.4

step-by-step explanation:

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