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Ch. 3 - Polynomial and Rational Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063당신이 사용하는 게 아니라요?교과서 변경
4장, 문제 9

Solve each problem. If m varies jointly as x and y, and m=10 when x=2 and y=14, find m when x=21 and y=8.

검증된 단계별 안내
1
Understand the concept of joint variation: If \( m \) varies jointly as \( x \) and \( y \), it means \( m \) is directly proportional to the product of \( x \) and \( y \). This can be written as the equation \( m = kxy \), where \( k \) is the constant of proportionality.
Use the given values \( m = 10 \), \( x = 2 \), and \( y = 14 \) to find the constant \( k \). Substitute these values into the equation \( m = kxy \) to get \( 10 = k \times 2 \times 14 \).
Solve for \( k \) by isolating it on one side of the equation: \( k = \frac{10}{2 \times 14} \).
Now that you have \( k \), use it to find \( m \) when \( x = 21 \) and \( y = 8 \). Substitute these values and \( k \) into the equation \( m = kxy \) to get \( m = k \times 21 \times 8 \).
Simplify the expression to find the value of \( m \) for the new values of \( x \) and \( y \).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
4m
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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Joint Variation

Joint variation describes a relationship where a variable depends on the product of two or more other variables. In this case, m varies jointly as x and y means m = kxy, where k is a constant. Understanding this helps set up the equation to find unknown values.

Constant of Variation

The constant of variation (k) is a fixed number that relates the variables in a joint variation equation. It is found by substituting known values of the variables into the equation m = kxy. Once k is determined, it can be used to find m for other values of x and y.
추천 영상:
6:02
Stretches & Shrinks of Functions

Substitution and Solving Equations

After finding the constant k, substitution involves replacing variables with given values to solve for the unknown. This process requires algebraic manipulation to isolate the desired variable, ensuring accurate calculation of m when x and y change.
추천 영상:
가이드 코스
5:48
Solving Systems of Equations - Substitution