A clothing store used the sign shown below to advertise a discount on shirts.
1 answer:
You might be interested in
Answer:
Equation: y=2x-1
Slope: 2
y-intercept: -1
Step-by-step explanation:
Hi there!
We are given the points (-1, -3) and (-2, -5). We need to find the slope, equation of the line, and the y intercept of the line
First, let's find the slope
The formula for the slope (m) calculated from two points is where (
,
) and (
,
) are points
We have everything we need for the formula, but let's label the values of the points to avoid any confusion
x1=-1
y1=-3
x2=-2
y2=-5
Now substitute into the formula (remember: the formula has SUBTRACTION):
m=
simplify
m=
add
m=
divide
m=2
So the slope is <u>2</u>
Now let's find the equation of the line
The question asks for it to be in slope-intercept form, which is y=mx+b, where m is the slope and b is the y intercept
We calculated the slope from earlier, so let's substitute that into the equation
y=2x+b
Now we need to find b
The equation will pass through both (-1, -3) and (-2, -5) so we can use either one of them to solve for b (doesn't matter which one)
Let's take (-1, -3) as an example
substitute -1 as x and -3 as y into the equation
-3=2(-1)+b
multiply
-3=-2+b
Add 2 to both sides
<u>-1=b (the value of the y intercept!) </u>
Substitute -1 as b into the equation
<u>y=2x-1</u>
We found everything needed for this problem
Hope this helps!