$\frac{4}{5}=\frac{}{15}$

Question

kaden2cool kaden2cool

05-11-2026
Mathematics

Answered

$\frac{4}{5}=\frac{}{15}$

Verified Answer :

Related Questions

help please asap

Which expression represents the phrase 8 less than the product of 6 and a number x

the farther you live from an ocean the more likely your climate will be a

When on November 11th 1918 an armistice was signed to end World War I the wars biggest losers were because their governments ceased to exist a the former indust

All of the following would be considered to be among the new media EXCEPT O direct mail O the Internet

A disadvantage of driving a motorcycle is that a you cannot stop as quickly as a car b you have less protection in a collision c either a or b

evaluate the effects of the teapot dome scandal on citizens views of the federal government

Which professionals most directly use geometry in their work a accountants b astronomers c judges d pharmacists epoliticians

When was the final loss of Jerusalem for the European forces The Crusades

An oil spill spreads 25 sqare meters every 16 hour how much does it cover in 2 hours

GinnyAnswer GinnyAnswer · Answer 1 · 2026-11-05T17:45:10-05:00

Identify the problem as a simple proportion $\frac{4}{5} = \frac{x}{15}$.
Use the property of equivalent fractions by observing that $15 = 5 \times 3$, requiring the numerator to be $4 \times 3 = 12$.
Alternatively, apply cross-multiplication to get $5x = 60$, which yields $x = 12$.
The final value for the unknown is $\boxed{12}$.

Explanation

Understanding the Problem

We are tasked with solving the proportion $\frac{4}{5} = \frac{x}{15}$, where $x$ represents the value in the box. A proportion is an equation stating that two ratios are equal. Our objective is to determine the value of $x$ that satisfies this equation. We can approach this problem in two ways: by finding equivalent fractions or by using the cross-multiplication method.

Solving using Equivalent Fractions

A convenient way to solve this is by finding an equivalent fraction. We observe that the denominator of the right-hand fraction, $15$, is related to the denominator of the left-hand fraction, $5$. Since $15 = 5 \times 3$, we know that the denominator has been multiplied by $3$. To ensure the two fractions remain equal, we must multiply the numerator of the first fraction by the same factor:
\[x = 4 \times 3 = 12\]
Thus, the fraction becomes $\frac{12}{15}$, which simplifies back to $\frac{4}{5}$.

Solving using Cross-Multiplication

Alternatively, we can use the method of cross-multiplication. For a proportion $\frac{a}{b} = \frac{c}{d}$, the property states that $a \cdot d = b \cdot c$. Applying this to our equation $\frac{4}{5} = \frac{x}{15}$:
\[4 \times 15 = 5 \times x\]
\[60 = 5x\]
To solve for $x$, we divide both sides of the equation by $5$:
\[x = \frac{60}{5} = 12\]
Both methods confirm the same result, and we find that the value to be placed in the box is $12$.

Examples

Ratios are essential in everyday life, such as scaling recipes. If a recipe for 5 people requires 4 cups of flour, and you are hosting a party for 15 people, you can use a proportion $\frac{4}{5} = \frac{x}{15}$ to find that you need 12 cups of flour. This ensures the correct balance of ingredients is maintained regardless of the number of guests.