How do you find the x- and y-intercept of the line 4x – 7y = 84?

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Answer 1 · 2017-04-21T03:09:44

See the entire solution process below:

y-intercept: Substitute $0$ $0$ for $x$ $x$ and solve for $y$ $y$ :

$4 x - 7 y = 84$ $4x - 7y = 84$ becomes:

$(4 \cdot 0) - 7 y = 84$ $(4 * 0) - 7y = 84$

$0 - 7 y = 84$ $0 - 7y = 84$

$- 7 y = 84$ $-7y = 84$

$\frac{- 7 y}{- 7} = \frac{84}{- 7}$ $(-7y)/color(red)(-7) = 84/color(red)(-7)$

$(color(red)(cancel(color(black)(-7)))y)/cancel(color(red)(-7)) = -12$

$y = -12$

The y-intercept is $-12$ or $(0, -12)$

x-intercept: Substitute $0$ for $y$ and solve for $x$ :

$4x - 7y = 84$ becomes:

$4x - (7 * 0) = 84$

$4x - 0 = 84$

$4x = 84$

$(4x)/color(red)(4) = 84/color(red)(4)$

$(color(red)(cancel(color(black)(4)))x)/cancel(color(red)(4)) = 21$

$x = 21$

The x-intercept is $21$ or $(21, 0)$