A linear equation has the unknown only to the first power. If appears on both sides, a Desmos regression can solve the original equation without rearranging it. First watch the negative factor outside the parentheses: it multiplies both terms inside. Changing a sign there means you’re solving a different equation.
Hints
- Hint 1
The distributive property says the number outside parentheses multiplies each term inside. Multiply by and by separately. What sign does the second product have?
- Hint 2
A solution makes both sides of an equation equal. To find it in Desmos, replace every with and with . Use the original equation so an error in distributing can’t change what you solve.
Step-by-step
Check the sign, then solve in Desmos
Step 1Distribute the negative factor
The distributive property multiplies by both terms inside 3x-4$$:7-2(3x-4)=5x+1\quad\Longrightarrow\quad 7-6x+8=5x+1.Negative times negative gives positive . Writing would change the equation.
- Step 2
Read the exact value of x
Type the original equation as . Desmos uses as the number to find, and tells it to make the two sides equal. Under PARAMETERS, it shows . Type on the next line and tap its fraction button to see . So . Choice C.