An equation with only to the first power is a linear equation. With parentheses on both sides, the outside number must multiply every term inside; missing one changes the equation. Check that distribution, then use a Desmos regression to find the value that makes the original two sides equal.
Hints
- Hint 1
The distributive property says a number outside parentheses multiplies every term inside. In , the multiplies the as well as the . What happens to the in ?
- Hint 2
A solution is a value of that makes both sides equal. To find it with a Desmos regression, keep both parentheses, change each to , and change the equals sign to .
Step-by-step
Approach 1: Check the distribution, then use Desmos
Step 1Distribute to every term
The distributive property sends to both and , and to both and . The outside number multiplies every term inside the parentheses. Distribute on both sides:
The negative term matters: , not .
- Step 2
Find the value that makes both sides equal
Type the original equation as . Desmos treats as the value to find, and tells its regression to make the sides equal. Under PARAMETERS, it shows . So the requested value of is . Grid in 12.
Approach 2: Balance both sides by hand
Step 1Combine the variable terms
Start with the distributed equation. Combine the like terms and , which both have an :
Their coefficients combine to make .
- Step 2
Combine the numbers on the right
Combine the constants, the numbers without :
Keep the negative sign on when adding .
- Step 3
Move the variable terms to one side
Subtract from both sides to keep them equal:
- Step 4
Isolate the variable term
Add to both sides:
- Step 5
Solve for x
Divide both sides by :
So the value of is . Grid in 12.