A = number of calls the first evening

b = = number of calls the second evening

c = number of calls the third evening

we know that she received a total of 99 calls, thus whatever "a", "b" and "c" are, we know that a + b + c = 99.

"The third evening, she received 4 times as many calls as the first evening"

c = 4a

"The second evening, she received 9 more calls than the first evening."

b = a + 9

 $\bf \begin{cases}
a+\underline{b}+\underline{c}=99\\
c=4a\\
b=a+9\\
----------\\
a+\underline{(a+9)}+\underline{(4a)}=99
\end{cases}
\\\\\\
a+a+9+4a=99\implies 6a=99-9\implies 6a=90\implies a=\cfrac{90}{6}$

and surely you know how much that is. Well, she got that many the first night.

how many the second night? well b = a + 9
what about the third night? well, c = 4a.

3 0

4 years ago

Solve the proportion for X. 5/2.5= X/2 1 4 5.5 6.25

Sav [38]

Answer:

$\large \boxed{X = 4}$

Step-by-step explanation:

5/2.5 = X/2

To solve a proportion, use the following equation:

(numerator * opposite denominator) = (numerator * opposite denominator)

Substitute in given numbers

(5 * 2) = (X * 2.5)

Multiply to simplify

10 = 2.5X

Divide both sides of this equation by 2.5

$\large \boxed{X = 4}$

Hope this helps :)

8 0

3 years ago