Solve for X: 6.8 + (1/5 + 2/10)x = (3/5)x - 2.2 Equation

Linear Equations with Mixed Fraction Coefficients

Solve for X:

6.8+15x+210x=35x2.2 6.8+\frac{1}{5}x+\frac{2}{10}x=\frac{3}{5}x-2.2

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Find X
00:04 Break down 10 into factors 2 and 5
00:21 Reduce what's possible
00:30 Collect terms
00:40 Arrange the equation so that X is isolated on one side
01:01 Collect terms
01:04 Isolate X
01:14 And this is the solution to the question

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

Solve for X:

6.8+15x+210x=35x2.2 6.8+\frac{1}{5}x+\frac{2}{10}x=\frac{3}{5}x-2.2

2

Step-by-step solution

We have the equation:

6.8+15x+210x=35x2.2 6.8 + \frac{1}{5}x + \frac{2}{10}x = \frac{3}{5}x - 2.2

To solve this equation, let's follow these steps:

  • Step 1: Convert all decimals to fractions for consistency and ease of calculation.
  • Step 2: Combine like terms on both sides of the equation.
  • Step 3: Rearrange the equation to isolate x x .
  • Step 4: Solve for x x .

Now, let's work through each step:

Step 1: Convert decimals to fractions:
6.8 6.8 can be written as 6810=345 \frac{68}{10} = \frac{34}{5} and
2.2 2.2 can be written as 2210=115 \frac{22}{10} = \frac{11}{5} .

Thus, the equation becomes:

345+15x+210x=35x115 \frac{34}{5} + \frac{1}{5}x + \frac{2}{10}x = \frac{3}{5}x - \frac{11}{5}

Step 2: Simplify the terms involving x x :

210 \frac{2}{10} simplifies to 15 \frac{1}{5} , so the left side becomes:

345+15x+15x=345+25x \frac{34}{5} + \frac{1}{5}x + \frac{1}{5}x = \frac{34}{5} + \frac{2}{5}x

Step 3: Move all terms involving x x to one side and constants to the other side:

Subtract 25x \frac{2}{5}x from both sides:

345=35x25x115 \frac{34}{5} = \frac{3}{5}x - \frac{2}{5}x - \frac{11}{5}

Combine terms:

345=15x115 \frac{34}{5} = \frac{1}{5}x - \frac{11}{5}

Step 4: Solve for x x by eliminating constants from the right side:

Add 115 \frac{11}{5} to both sides:

345+115=15x \frac{34}{5} + \frac{11}{5} = \frac{1}{5}x

Combine the constants on the left:

455=15x \frac{45}{5} = \frac{1}{5}x

Since 455=9 \frac{45}{5} = 9 , it follows:

9=15x 9 = \frac{1}{5}x

Finally, multiply both sides by 5 to isolate x x :

x=9×5 x = 9 \times 5

x=45 x = 45

Therefore, the solution to the equation is x=45 x = 45 .

3

Final Answer

45 45

Key Points to Remember

Essential concepts to master this topic
  • Simplification: Convert all decimals to fractions for easier calculation
  • Technique: Combine like terms: 15x+210x=25x \frac{1}{5}x + \frac{2}{10}x = \frac{2}{5}x
  • Check: Substitute x = 45: 6.8+25(45)=35(45)2.2 6.8 + \frac{2}{5}(45) = \frac{3}{5}(45) - 2.2 gives 24.8 = 24.8 ✓

Common Mistakes

Avoid these frequent errors
  • Adding fractions with different denominators incorrectly
    Don't add 1/5 + 2/10 = 3/15 = wrong answer! This creates an incorrect coefficient that throws off the entire solution. Always convert to common denominators first: 1/5 + 2/10 = 2/10 + 2/10 = 4/10 = 2/5.

Practice Quiz

Test your knowledge with interactive questions

Solve for X:

\( 6 - x = 10 - 2 \)

FAQ

Everything you need to know about this question

Why should I convert decimals to fractions?

+

Converting decimals like 6.8 and 2.2 to fractions eliminates rounding errors and makes combining terms easier. Working with 345 \frac{34}{5} and 115 \frac{11}{5} is more precise than decimals!

How do I combine the x terms on the left side?

+

First convert 210 \frac{2}{10} to 15 \frac{1}{5} , then add: 15x+15x=25x \frac{1}{5}x + \frac{1}{5}x = \frac{2}{5}x . Always use common denominators before adding fractions!

What if I get confused moving terms to different sides?

+

Use the same operation on both sides rule! To move 25x \frac{2}{5}x from left to right, subtract it from both sides. Keep your work organized by writing each step clearly.

Why is my final answer so large (45)?

+

Large answers are common when dealing with fractions! The small coefficient 15 \frac{1}{5} means x must be 5 times larger to balance the equation. Always verify large answers by substitution.

Can I solve this without converting to fractions?

+

Yes, but it's much harder and more error-prone! Working with decimals like 0.2x creates rounding issues. Fractions give exact answers and cleaner calculations.

How do I check if x = 45 is really correct?

+

Substitute back: Left side = 6.8+15(45)+210(45)=6.8+9+9=24.8 6.8 + \frac{1}{5}(45) + \frac{2}{10}(45) = 6.8 + 9 + 9 = 24.8
Right side = 35(45)2.2=272.2=24.8 \frac{3}{5}(45) - 2.2 = 27 - 2.2 = 24.8
Both sides equal 24.8, so x = 45 is correct!

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Linear Equations (One Variable) questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations