X+y=156
0.05x+0.25y=21.6

-1/4*/ x+y=156
1/20x+1/4y=216/10

-1/4x-1/4y=156*-1/4=-39

1/20x+1/4y=216/10
+--------------------------
-4/20x=-17,4

x=87

x+y=156

87+y=156 y=69

this question answer is 87 nickels and 69 quarters

3 0

2 years ago

Please Help ASAP with Math

vampirchik [111]

Answer:

5.33

Step-by-step explanation:

move the 4 out of the summation because just a constant multiplier

4 *sum from 1 to 10 for (1/4)^(n-1) [sorry i don't know how to write sums using latex)

The formula for the geometric sum is :

First term*(1-multiplier^n)/(1-multiplier), formally $\frac{a_1(1-r^n)}{1-r}$

Here multiplier is 1/4

First term is (1/4)^(1-1) = 1

Thus the value of sum is $1*(1-(1/4)^1^0)/(1-1/4)$ which equals $(1- (1/4)^1^0)*4/3$

We factored out 4 so its $4*(1-(1/4)^1^0)*4/3$ which is $16/3 * (1- (1/4)^1^0)$

This equals 5.333328247 which is 5.33 to the nearest hundredth

5 0

1 year ago

597008.439431 to the nearest thousand

vodka [1.7K]

597008.439431 rounded to the nearest thousandth is 597008.439, because a thousandth place is 3 decimal places available, to the right.

5 0

2 years ago

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