The slope of this line is -1/6.
2 Point: (6,2) (-6,6)
x₁ y₁ x₂ y₂
Remember:
rise change in y y₂ - y₁ 6 - 2 4
---------- = ------------------- = ------------- = ----------- = ----------
run change in x x₂ - x₁ -6 - 6 -12
Simplify 4/-12
4 ÷ 4 1
------- = ------------- = -1/3
-12 ÷ 4 -3
The slope of the line is -1/3.
You've got five different problems in this photo ... four on top and the word problem on the bottom ... and they're all exactly the same thing: Taking two points and finding the slope of the line that goes through them.
In every case, the procedure is the same.
If the two points are (x₁ , y₁) and (x₂ , y₂) , then
the slope of the line that goes through them is
Slope = (y₂ - y₁) / (x₂ - x₁) .
This is important, and you should memorize it.
#1). (8, 10) and (-7, 14)
Slope = (14 - 10) / (-7 - 8) = 4 / -15
#2). (-3, 1) and (-17, 2)
Slope = (2 - 1) / (-17 - -3) = (2 - 1) / (-17 + 3) = 1 / -14
#3). (-20, -4) and (-12, -10)
Slope = [ -10 - (-4) ] / [ -12 - (-20) ]
=========================================
The word problem:
This question only gives you one point on the graph,
and then it wants to know what's the slope ?
What are you going to do for another point ?
A "proportional relationship" always passes through the origin,
so another point on the line is (0, 0) .
Now you have two points on THAT line too, and you can easily
find its slope.
7 minutes is the answer i think but dont quote me on that
X-1.5=21
+1.5 +1.5
x=22.5
22.5-1.5=21 Subtraction sentence
