Question

Using the formula y=mx+b whats the equation of (2,-8) with a slope of -1?

Answer 1

Answer:

y = -x - 6

Step-by-step explanation:

Given:

• slope = -1
• point (2,-8)

From:

$\displaystyle \large{y=mx+b}$

where m = slope and b = y-intercept. Therefore:

$\displaystyle \large{y=-1x+b}\\\displaystyle \large{y=-x+b}$

Since the equation passes through a point (2,-8). Substitute x = 2 and y = -8 in and solve for b:

$\displaystyle \large{-8=-2+b}\\\displaystyle \large{-8+2=b}\\\displaystyle \large{b=-6}$

Then substitute b-value in the equation:

$\displaystyle \large{y=-x+b}\\\displaystyle \large{\therefore y=-x-6}$

Hence, the equation is y = -x - 6

Answer 2

Answer:

y = -x - 6

Step-by-step explanation:

Hi there!

We are given that a line contains the point (2, -8), and a slope of -1

We want to find the equation of this line, in slope-intercept form

Slope-intercept form is written using the formula y=mx+b, where m is the slope and b is the value of y at the y intercept, hence the name

Notice how we are already given the slope - we can immediately plug that into the equation as m.

y = -x + b (when -1 is the coefficient in front of a number, there is no need to write '-1x'. '-x' is sufficient.)

Now, we need to find b

The line contains the point (2, -8), meaning that it is a solution to the equation. If this is the case, that means that the values of x and y that make up the point will make the equation true, when you plug those values into the equation

So substitute 2 as x and -8 as y:

-8 = -2 + b

Add 2 to both sides

-8 = -2 + b

+2    + 2

_____________

-6 = b

Substitute -6 as b.

y = -x -6

Hope this helps!

See more on finding the equation of the line using a point & the slope here: brainly.com/question/25508767