SOLUTION: Solve and graph 3x+4y=-16

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Question 1201200: Solve and graph
3x+4y=-16

Found 3 solutions by mananth, Theo, josgarithmetic:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
what is to be solved?

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
3x + 4y = -16
subtract 3x from both sides of the equation to get:
4y = -16 - 3x
divide both sides of the eqution by 4 to get:
y = -16/4 - 3/4 * x
order the equation in descending order of degree and simplify to get:
y = -3/4 * x - 4
it has a slope of -3/4 and a y-intercept of -4.
the x-intercept is the value of y when the value of x is 0.
start with y = -3/4 * x - 4
set y = 0 to get 0 = -3/4 * x - 4
add 4 to both sides of the equation to get:
4 = -3/4 * x
divide both sides of the eqution by -3/4 to get:
4 / (-3/4) = x
solve for x to get:
x = -5.33333.....
here's a graph of the original equation, using the desmos.com calculator.

you can see that the y-intercept is x = -4
that's the value of y when the value of x is zero.
you can see that the x-intercept is y = -5.333.
that's the value of x when the value of y is zero, rounded to 3 decimal places.
you can see that the slope is -3/4 because, looking from left to right, you have the coordinate point of (-5.33333....., 0) and the coordinate point of (0,-4) on the line.
the slope is (y2-y1) / (x2-x1) = (-4 - 0) / (0 + 5.33333.....) = (-4 - 0) / 5.33333.....
this is equal to -4 / (16/3) which is equal to -3/4.


Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
3x%2B4y=-16
3x%2F4%2By=-4
y=-%283%2F4%29x-4
You see from this SLOPE is -3%2F4 and y-axis intercept is -4, and you have enough information to make the graph.