Straight line graph part three

Remember also that y = 0 is the x-axis.

For the straight line y = 2x + 1, what is the value of x when y = 0? Thus is the same question as what is the vale of x when the line crosses the x-axis.

y = 2x + 1

o = 2x + 1

2x + 1 = 0

2x = -1

x =  -\frac{1}{2}

We can see this on the graph. When the line crosses the x-axis x =  -\frac{1}{2}