Question

How do you graph `y=2x+10`?

Answer 1

see explanation

Explanation:

This is the equation of a straight line. One way of graphing is to find where the line crosses the axes.
When the line crosses the y-axis , the x-coord will be zero. Letting x = 0 and substituting into the equation will give the y coordinate.

let x = 0 : y = 0 + 10 = 10 hence (0,10) is a point on line.

Similarly when the line crosses the x-axis , the y-coord will be zero.

let y = 0 : 2x + 10 = 0 → 2x = -10 → x = -5 (-5,0) is a point on line.

Two points are all that is required to draw a line , however , a third is useful in helping with alignment.

choose any value of x for this , say x = -1

let x = -1 : y = -2 + 10 = 8 → (-1,8) is a point on the line.

Now plot (0,10) , (-5,0) and (-1,8) and draw a straight line through them.

Here is the graph of the line for comparison.
graph{2x+10 [-20, 20, -10, 10]}