Question

1. Find the x and y intercept for the function 3x-4y=12

Answer 1

Answer: x-intercept = (4, 0) ; y-intercept = (0, -3)

Explanation:

To easily solve this problem we need to know two facts:

1. the y-intercept is 'c' when a line is in the slope-intercept form (y = mx + c)
2. the x-intercept occurs when y = 0

Slope-intercept form

Since 3x - 4y = 12

3x - 12 = 4y

y = ³/₄ x - 3

∴ y-intercept is (0, -3)

Solve for x when y = 0

Since 3x - 4y = 12

3x - 4(0) = 12

x = 4

∴ x-intercept is (4, 0)

We can check our answer by graphing the line and seeing if it passes through the intercepts we calculated. Since it does (see graph below), then the answers we calculated are correct.