Question

A line has a slope of 9 and passes through the point (2, 8). What is its equation in slope-intercept form? Explain?

Answer 1

Answer: y= 9x-10


Step 1: Write equation in slope- intercept form

In the question, we are asked to write an equation for a line in slope- intercept form. For step 1, let’s write the standard formula.

y= mx+b

Step 2: Substitute information

To solve the equation, we must first substitute the numbers into the equation. Let’s first substitute the slope, which will replace the letter m.

y= mx+b
y= 9x+b

Now let’s put the point into the equation. It will not stay in the equation like 9, but it help us find the numeric value of b. Let’s put this in now.

y= 9x+b
8= 9(2)+b

Step 3: Solve for b

Let’s now solve our equation for b.

8= 9(2)+b
8= 18+b
-10= b

Step 4: Write final equation

We know the value for b, so we can now substitute this into the equation for our final answer. Keep in mind that the point will not stay in, and y and x will remain a variable.

y= mx+b
y= 9x+b
y= 9x-10

This is your answer! Our equation is y=9x-10. Hope this helps! Comment below for more questions.

Answer 2

y = 9x-10

Explanation:

Slope-Intercept form is y = mx + b where m is the slope and b is the y intercept.

plug in what we are given

8 = 9(2) + b

solve for the y intercept (b)

8=18+b

8-18 = b

-10 = b

plug the slope (m) and y intercept (b) into our formula

y = 9x - 10