Question

Difficulty: EasyLinear Equations in One Variable

If x2+x3=10\frac{x}{2} + \frac{x}{3} = 10, what is the value of xx?

  1. A
    25
  2. 12Answer
  3. C
    2
  4. D
    6
  5. E
    15

Answer

The value of xx is 12.
The option showing 12 is correct because converting the fractions x2\frac{x}{2} and x3\frac{x}{3} to have a common denominator of 6 produces 3x+2x6=10\frac{3x + 2x}{6} = 10, or 5x6=10\frac{5x}{6} = 10. Multiplying both sides by 6 gives 5x=605x = 60, and dividing by 5 yields x=12x = 12.

Step-by-Step Solution

1
Find a common denominator for the fractional terms on the left side of the equation.
The least common denominator of 2 and 3 is 6. Rewriting the fractions gives 3x6+2x6=10\frac{3x}{6} + \frac{2x}{6} = 10.
Fractions must have identical denominators before their numerators can be added.
2
Combine the fractions on the left side.
5x6=10\frac{5x}{6} = 10
Adding the numerators 3x+2x3x + 2x yields 5x5x over the shared denominator 6.
3
Clear the denominator by multiplying both sides of the equation by 6.
5x = 60
Multiplying both sides by 6 eliminates the fraction while maintaining equality.
4
Isolate xx by dividing both sides by 5.
x = 12
Dividing 60 by 5 yields the solution for xx.

Key Concept

Solving linear equations involving fractions by clearing denominators using the least common multiple.
Estimated Time:45s
Rate this question