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I need help with my math

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4 votes

Question:

Solution:

Let the following linear function:


4x\text{ + 5y = 20}

solve for 5y:


5y\text{ = }20-4x

solving for y, we get:


y\text{ = }-(4)/(5)x\text{ + }4

the y- intercept is when x = 0, then replacing x = 0 into previous equation we get:


y\text{ = }-(4)/(5)(0)\text{ + }4\text{ = 4}

then the y-intercept is the point:

(x,y) = (0,4)

Now, the x-intercept is when y = 0, the replacing y = 0 into the equation:


y\text{ = }-(4)/(5)x\text{ + }4

we get:


0\text{ = }-(4)/(5)x\text{ + }4

this is equivalent to:


-4\text{= }-(4)/(5)x\text{ }

this is equivalent to:


4\text{= }(4)/(5)x\text{ }

solving for x, we get:


x\text{ = }(20)/(4)\text{ = 5}

then the x-intercept is the point:

(x,y) = (5,0)

Then, we can conclude that the correct answer is:

1. the y-intercept is the point (x,y) = (0,4).

2. the x-intercept is the point (x,y) = (5,0).

and the graph of the line is:

I need help with my math-example-1
I need help with my math-example-2
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