Question

Explain how to find the x-intercept of the graph of y = 4x - 2.

Answer 1

There are two ways to do this. The first of which is the algebraic method. Plug in y = 0 and solve for x.

y = 4x - 2

0 = 4x - 2 ... y is replaced with 0

4x-2 = 0

4x-2+2 = 0+2 ... we add 2 to both sides

4x = 2

4x/4 = 2/4 .... divide both sides by 4

x = 1/2

x = 0.5

The x intercept is x = 1/2 or x = 0.5

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The other approach is to graph the equation y = 4x-2, and mark where the line crosses through the x axis. You should find it crosses through x = 1/2 or x = 0.5; the x intercept as an ordered pair would be (1/2, 0) or (0.5, 0)

side note: the equation y = 4x-2 goes through the points (0,-2) and (1,2). You find this by plugging in x = 0 and x = 1 respectively to find the corresponding y values.