Let’s go through each problem one by one. We’ll simplify the expressions step by step, just like you would on homework.
---
Problem 1:
\[
\frac{3x}{2} + \frac{4x}{5}
\]
To add fractions, we need a common denominator. The least common denominator of 2 and 5 is
10.
Convert each fraction:
- \(\frac{3x}{2} = \frac{3x \cdot 5}{2 \cdot 5} = \frac{15x}{10}\)
- \(\frac{4x}{5} = \frac{4x \cdot 2}{5 \cdot 2} = \frac{8x}{10}\)
Now add:
\[
\frac{15x}{10} + \frac{8x}{10} = \frac{23x}{10}
\]
✔ Matches the red answer.
---
Problem 2:
\[
\frac{x}{2} + \frac{4x}{5}
\]
Common denominator = 10
- \(\frac{x}{2} = \frac{5x}{10}\)
- \(\frac{4x}{5} = \frac{8x}{10}\)
Add:
\[
\frac{5x}{10} + \frac{8x}{10} = \frac{13x}{10}
\]
✔ Correct.
---
Problem 3:
\[
\frac{x}{2} + \frac{x}{5}
\]
Common denominator = 10
- \(\frac{x}{2} = \frac{5x}{10}\)
- \(\frac{x}{5} = \frac{2x}{10}\)
Add:
\[
\frac{5x}{10} + \frac{2x}{10} = \frac{7x}{10}
\]
✔ Correct.
---
Problem 4:
\[
\frac{x}{2} - \frac{x}{5}
\]
Common denominator = 10
- \(\frac{x}{2} = \frac{5x}{10}\)
- \(\frac{x}{5} = \frac{2x}{10}\)
Subtract:
\[
\frac{5x}{10} - \frac{2x}{10} = \frac{3x}{10}
\]
✔ Correct.
---
Problem 5:
\[
\frac{x}{5} - \frac{x}{2}
\]
Common denominator = 10
- \(\frac{x}{5} = \frac{2x}{10}\)
- \(\frac{x}{2} = \frac{5x}{10}\)
Subtract:
\[
\frac{2x}{10} - \frac{5x}{10} = -\frac{3x}{10}
\]
✔ Correct.
---
Problem 6:
\[
\frac{5x}{5} - \frac{x}{2}
\]
First, simplify \(\frac{5x}{5} = x\)
So now: \(x - \frac{x}{2}\)
Write \(x\) as \(\frac{2x}{2}\):
\[
\frac{2x}{2} - \frac{x}{2} = \frac{x}{2}
\]
✔ Correct.
---
Problem 7:
\[
\frac{5}{x} + \frac{2}{x}
\]
Same denominator → just add numerators:
\[
\frac{5 + 2}{x} = \frac{7}{x}
\]
✔ Correct.
---
Problem 8:
\[
\frac{5}{x^2} + \frac{2}{x}
\]
Need common denominator. Since \(x^2\) is bigger, use that.
Convert \(\frac{2}{x}\) to have denominator \(x^2\):
\[
\frac{2}{x} = \frac{2 \cdot x}{x \cdot x} = \frac{2x}{x^2}
\]
Now add:
\[
\frac{5}{x^2} + \frac{2x}{x^2} = \frac{2x + 5}{x^2}
\]
✔ Correct.
---
Problem 9:
\[
\frac{5}{2x^2} - \frac{2}{x}
\]
Common denominator = \(2x^2\)
Convert \(\frac{2}{x}\) to denominator \(2x^2\):
Multiply numerator and denominator by \(2x\):
\[
\frac{2}{x} = \frac{2 \cdot 2x}{x \cdot 2x} = \frac{4x}{2x^2}
\]
Now subtract:
\[
\frac{5}{2x^2} - \frac{4x}{2x^2} = \frac{5 - 4x}{2x^2}
\]
✔ Correct.
---
Problem 10:
\[
\frac{6}{2x^2} - \frac{2}{x}
\]
First, simplify \(\frac{6}{2x^2} = \frac{3}{x^2}\)
Now: \(\frac{3}{x^2} - \frac{2}{x}\)
Common denominator = \(x^2\)
Convert \(\frac{2}{x} = \frac{2x}{x^2}\)
Subtract:
\[
\frac{3}{x^2} - \frac{2x}{x^2} = \frac{3 - 2x}{x^2}
\]
✔ Correct.
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All answers match the red ones shown. So if this was your homework, you got them all right!
Final Answer:
All given solutions are correct.
Parent Tip: Review the logic above to help your child master the concept of adding and subtracting algebraic expressions worksheet.