A system of equations with infinitely many solutions is a system where the two equations are identical. The lines coincide. Anything that is equal to

will work. You could try multiply the entire equation by some number, or moving terms around, or adding terms to both sides, or any combination of operations that you apply to the entire equation.
You could multiply the whole thing by 4.5 to get

. If you want, you could mix things up and write it in slope-intercept form:

. The point is, anything that is equivalent to the original equation will give infinitely many solutions x and y. You can test this by plugging in values x and y and seeing the answers!
The attached graph shows that four different equations are really the same.
Answer:
(a) The amount of ice cream increase as temperature increases
(b)
--- equation
--- y intercept
--- slope
Step-by-step explanation:
Given
See attachment for graph
Solving (a): The relationship between the variables
From the attached graph, the dots on the graph increases towards up-right direction. This implies that there is a positive correlation between the variables.
In other words;
The amount of ice cream increase as temperature increases
Solving (b): The line of best fit
First, we draw a line through the points (the line should have almost equal points on both sides; see attachment 2).
From (2), we select any 2 points on the line:


The slope (m) is:




So, the line of best fit is:

Substitute known values:



The y-intercept is when 
So, we have:



Y=-2x+0 haahahaha hope i helped i think