A linear equation has the unknown only to the first power. Fractions on both sides make this a good equation to enter directly in Desmos: change to and to , then read the value under PARAMETERS. Keep the second numerator together when typing the subtraction. If Desmos shows a repeating decimal, use its fraction button to get the exact value.
Hints
- Hint 1
A solution is a value of that makes both sides equal. For a one-variable equation in Desmos, replace every with and the equals sign with . Be careful to subtract the entire second fraction.
- Hint 2
A repeating decimal may represent an exact fraction. After Desmos reports under PARAMETERS, type on its own line and press the fraction button. You can then compare the exact value with the choices.
Step-by-step
Approach 1: Solve the fraction equation in Desmos
Step 1Find the value that makes both sides equal
Type the equation below, changing every to and to . Desmos uses for graphing; the regression sign tells it to find the value of that makes both sides equal. Under PARAMETERS, it shows . Keep together in the numerator so the minus sign subtracts the whole fraction.
- Step 2
Read the exact solution
Type on a new line. Desmos displays its decimal value; press that line's fraction button to display . Since stands for the equation's , the value that satisfies the equation is . Choice B.
Approach 2: See why the x-terms cancel
Step 1Clear the fractions
The denominators are the bottom numbers , , and . Multiply every term on both sides by , which each denominator divides into:
- Step 2
Distribute the negative multiplier
Distribute to both terms inside ; don't change only the term: . The minus sign reaches the , too.
- Step 3
Combine the left side
Combine like terms, which have the same variable part, and combine the plain numbers: . The and cancel, so the whole left side is a constant.
- Step 4
Expand the right side
Distribute to both terms inside : . The multiplies as well as .
- Step 5
Isolate the x-term
Add to both sides to keep the equation equal:
- Step 6
Find x
Divide both sides by : . So satisfies the equation. Choice B.