Question

What is the solution to x+y=3

Answer 1

When x = 0 then y=3 point (0,3)
when y = 0 then x = 3 point (3,0)
opposite way round
when x=0 then 0-y=3 which means y = -3. point (0,-3)
when y=0 then x-0=3 which means y = 3. point (3,0)
draw a line going through points (0,3) and (3,0)
and a line going through points (0,-3) and point (3,0)

Answer 2

Step 1. Intercepts occur when one of the coordinates is equal to 0. So the y-intercept occurs at x=0 and the x-intercept occurs at y=0. 

Step 2. It takes two points to make a line. So use these intercepts points 

Step 3. When x=0, then 0-y=3 or y=-3. So we have point (0,-3). 

Step 4. When y=0, then x-0=3 or x=3. So we have another point (3,0). 

Step 5. Graph the line as shown below using these two points found in Steps 3 and 4. 

 


Note x-y=3 can be written as y=x-3 in slope-intercept form where slope m=1 and y-intercept b=-3.