N = nickels and q = quarters

0.05n + 0.25q = 1.90
n = 2q + 3

0.05(2q + 3) + 0.25q = 1.90
0.10q + 0.15 + 0.25q = 1.90
0.10q + 0.25q = 1.90 - 0.15
0.35q = 1.75
q = 1.75/0.35
q = 5 ......there are 5 quarters

n = 2q + 3
n = 2(5) + 3
n = 10 + 3
n = 13 <=== there are 13 nickels

6 0

3 years ago

Help please:Suppose that x and y inversely, and x=10 when y=8 write the function that models the inverse variation

jarptica [38.1K]

SOLUTION

From the question, we are told that y varies inversely as x

This is mathematically written as

$\begin{gathered} y\propto\frac{1}{x} \\ \propto\text{ is a sign of proportionality } \end{gathered}$

Now, we will remove the proportionality sign and replace it with equal to sign =

If we do this, we will intoduce a constant k

$\begin{gathered} y\propto\frac{1}{x} \\ y=k\times\frac{1}{x} \\ y=\frac{k}{x} \end{gathered}$

So we have the formula

$y=\frac{k}{x}$

We will substitute the values of x for 10 and y for 8 into the formula to get k, we have

$\begin{gathered} y=\frac{k}{x} \\ 8=\frac{k}{10} \\ k=8\times10 \\ k=80 \end{gathered}$

Now, we will substitute k for 80 back into the formula to get the inverse function, we have

$\begin{gathered} y=\frac{k}{x} \\ y=\frac{80}{x} \end{gathered}$

Hence the answer is option C

7 0

1 year ago

Select the polynomial that can be factored as (4x-5)(16x^2+20x+25)

bezimeni [28]

f(x) = 64x³ - 125

Multiply each term in the second factor by each term in the first factor

= 4x(16x² + 20x + 25) - 5(16x² + 20 x + 25)

=64x³ + 80x² + 100x - 80x² - 100x - 125

= 64x³ - 125 ← difference of cubes

5 0

3 years ago