Explanation:
Please correct me if I do something different from your class and I'll try to change my answer to match the expectations of your class.
A linear equation is an equation depicting a linear relationship between variables x and y, or any two variables for that matter.
Typically, it's written as y = mx + b. But, an alternative way to write it is by using standard form, which is:
ax + by = c
The equation of y=mx+b is slope-intercept form, but standard form allows us to see that the combination of the two variables (in this case the two flavors of ice cream) can vary, as long as they equal the c value (the total money generated).
So, let's assign variables to two variables:
For ease of typing, I'm calling mint chocolate chip as "mint" and vanilla caramel swirl as "caramel":
"x" will be the amount of mint ice cream sold, and "y" will be the amount of vanilla sold.
We need to attach the price constant to these two, as we want our function to represent how much money both ice cream generated, which is 150$.
2x + 4y = 150
So, here's how to read this equation:
"x" and "y" are free to be any value, as long as it equals 150. So, when it's graphed, it's a straight line. That x and y value combined (and placed into our equation) will always equal 150.
If no mint is sold, y is 37.5 ice cream sold, and if no vanilla is sold, then x is 75 ice cream sold.
Now to graph it, here are ways you can do it:
- Transform it back into slope-intercept form by isolating one variable (typically "y" on one side), so your equation resembles y = mx + b
- Use the two points we found (0, 37.5 and 75,0) to find the slope, and create your slope-intercept equation that way.
- Lazy way, but just draw those two points and create a straight line.