Yuri & Kaoru's Weight Loss Journey
By: Juhi Bora
Yuri loses 3 pounds each month.
Kaoru loses 7 pounds each month.
When will Yuri and Kaoru's weight be the same?
Yuri's Weight Loss Table
Equation (Yuri) :
Kaoru's Weight Loss Table
Equation (Kaoru) :
Desmos Graphic Solution
1. Plot the y-intercept which is (0,180).
2. From that point, use the slope (-3/1 or -3) to graph the line
1. Plot the y-intercept which is (0,212).
2. From that point, use the slope (-7/1 or -7) to graph the line
Now you can look at the graph a find the point of intersection/solution, which is (8,156).
You can also find the solution with the process of substitution-
If y=y, then that means...-3x+180 = -7x+212
-3x+180 = -7x+212
-3x+7x = 212-180
4x = 32
x = 8
Now we can substitute x into one of the equations to find y
So now you know that x=8 and y=156, therefore the point of intersection is (8,156).
You can also find the solution with the process of elimination-
You know that these two equation both have y in common, so we're going to eliminate by making one of the equation negative and subtracting in from the other. This way the positive and negative y, will cancel out.
y= -3x +180
-(y= -7x +212)
0= 4x - 32
32 = 4x
32/4 = x
Now that we know what x is, we can substitute x in one of the equation to find y.
y= -3(8) +180
y= -24 + 180
Therefore the point of intersection/solution is (8,156).