Question 289·Easy·Math

0 / 2000

If $5y - 15 = 0$ , what is the value of $8y$ ?

Your answer

A linear equation has a variable to the first power. If the question asks for a multiple of that variable, solving the equation is only the first job. A one-variable regression in Desmos can find the variable’s value. Then evaluate the expression the question actually asks for.

Hints

Hint 1
For a one-variable regression, Desmos finds the number that makes both sides of an equation match. Replace $y$ with $x_1$ and use $\sim$ in place of $=$ . What value does it find?
Hint 2
The value of $y$ is not yet the requested value. Once Desmos finds $x_1$ , type the expression from the question using $x_1$ in place of $y$ .

Step-by-step

Solve and finish in Desmos
Step 1
Find the value of y
The given equation has one unknown, $y$ . Replace $y$ with $x_1$ and type $5x_1-15\sim 0$ . Desmos treats $x_1$ as the number to find, and $\sim$ tells it to match the two sides. Under PARAMETERS, it shows $x_1=3$ , so $y=3$ .
Step 2
Evaluate what the question asks for
The question asks for eight times $y$ , not $y$ alone. Type $8x_1$ on the next line. Desmos prints $24$ , so $8y=24$ . Grid in 24.

Question 289·Easy·Math

Strategy

Hints

Step-by-step

Lessons that teach this

Study Hints

Strategy

Hints

Step-by-step

Lessons that teach this