Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.

Video: Writing and Solving Two-Variable Linear Equations Involving Multiplicative Comparison

Kathryn Kingham

Fish A is 2 times as long as fish B. Write an equation to determine the length of fish B if fish A is 6 meters long, and then solve it.

02:20

Video Transcript

Fish A is two times as long as fish B. Write an equation to determine the length of fish B if fish A is six meters long and then solve it.

Here’s what we know, that fish A is two times as long as fish B. We also know that fish A is six meters long. We wanna take the information that we’ve been given, the sentence, and turn it into an equation.

When we see the word “is” in a sentence, we can translate that into an equal sign. We can say fish A equals. We have the number two that won’t change; it’ll also be the number two in our equation. Then we have the phrase times as, which is just multiplication, times. As long as fish B, but our equation doesn’t tell us how long fish B is. You can just leave that as 𝑥; we don’t know. But we do know how long fish A is. Fish A is six meters long.

Here’s our new equation: six equals two times 𝑥 or six equals two 𝑥, where 𝑥 is the length of fish B. So what is 𝑥? What is the length of fish B? We’re asking the question, What times two equals six? Six equals two times three. This means that 𝑥 equals three, and the length of fish B is three meters.