How can we write an expression to show 3 less than a number?
 start by drawing a diagram to model the subtraction. are we taking away from the 3 or the unknown number?
 what expression would represent this model?

x - 3

Step-by-step explanation:

Let x be the unknown number,

For making the diagram to model this problem,

Take a grid that shows x,

Divide this grid into two parts,

If first part is of 3 then second part would be x - 3

That is, we are taking away 3 from the unknown number,

Hence, the required expression would be x - 3

gregory's graph is incorrect because it shows 2 inches of growth for each week when it should show 0.75 inches of growth each week.

see below

step-by-step explanation:

x+2> 6

subtract 2 from each side

x+2-2 > 6-2

x > 4

there is an open circle at 4 since is it is greater than and the line goes to the right