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Lesson 4: One-step multiplication and division equations

# One-step multiplication equations: fractional coefficients

Learn how to solve equations with fractions by using reciprocals. Multiply both sides of the equation by the reciprocal of the fraction to make the coefficient one. This simplifies the equation, making it easier to find the value of the variable. Created by Sal Khan.

## Want to join the conversation?

• I tried calculating the first sum on my own and did a completely in a different way compared to the way Sal had explained and demonstrated it...And I checked if my answer was correct and it was so....What should I do? Should I keep doing it the way I did it or should I do it the way Sal had?
• My advice is that you should try both ways first, and then go with the answer that feels right to you, and then check your answer. Have a nice day!
• Math can be confusing and this is very hard Help meeee. This also makes 0 sense.
• another tip when multiplying fractions by fractions if there is an expression is to:
multiply d by d and n by n.
for fraction by fraction division you can do the first n divided by the second d and the second n by the first d then multiply the 2 fractions you got.
• dude im so lost XD
• Do you understand one step equations with division or multiplication? If you have 3x = 9, coefficients indicate multiplication, so opposite is division, divide by 3 on both sides, 3/3 x = 9/3. If you have x/4=2, opposite of divide is multiply, so multiplying by 4 gives 4^x/4=2*4, so x=8. If you understand these two, fractions are just combining these two separate things into 1, if you have 3/4 x = 15, then multiply by 4 and divide by 3 gives 4/3 * 3/4 x = 15* 4/3, so x=20. Opposites of fractions are their reciprocal.
• How do you get 12/15 from 10.6= 12/15c/2?
I don't understand at all.
At Sal says,
"To get a variable do it".
How does that make any sense?
• Can someone else explain this to me shorter and easier to understand
• Basically, if you have a variable with a coefficient that is a fraction, such as 1/4x = 5, you can multiply both sides by the reciprocal of the coefficient to find what the variable is.

1/4 x 4/1 = 1
5 x 4/1= 20
x = 20

Hope this helped!
• 4/3b = 4/5
What is b?

I’m very confused, I found the LCM of them, but i have to multiply 20/15 by some number to get 12/15. What? ? ?
• Do you understand one step equations with division or multiplication? If you have 3x = 9, coefficients indicate multiplication, so opposite is division, divide by 3 on both sides, 3/3 x = 9/3. If you have x/4=2, opposite of divide is multiply, so multiplying by 4 gives 4^x/4=2*4, so x=8. If you understand these two, fractions are just combining these two separate things into 1, if you have 3/4 x = 15, then multiply by 4 and divide by 3 gives 4/3 * 3/4 x = 15* 4/3, so x=20. Opposites of fractions are their reciprocal.
• Why is there no comments 🤨
(1 vote)
• It is because this is a new video. Many people have not watched it yet.
• Hi How old are you?
(1 vote)
• We probably spent like five hours of just watching math videos
(1 vote)
• 1.2 = 1.5k

WHAT XD how does 1.2 = 1.5k? XD

1.2 ≠ 1.5k