how do i get the points?

Question

solve the system of equations

5x+y=-5
y=-5

i lost. pleasse help. i need to graph these by finding 3 solution sets and i suck at algebra :(

Answer 1

Just substitute y=-5 into the top equation to get: 5x-5=-5
so 5x=0 which means that y=0.

Answer 2

To solve, the first thing you do is substitute y with its value from the 2nd equation into the first:
5x + (-5) = -5

Now solve for x. Add five to both sides.

5x + (-5) + 5 = -5 + 5

Simplify:
5x = 0

So x has to be zero, because 5 x 0 = 0.

Check your answer with equation 1:
5 x 0 + (-5) = -5

0 - 5 = -5 (checked)

OK. How do you graph all this?

Well the graph of the line y = -5 is simple. The x-axis is horizontal, the y-axis is vertical. Draw a horizontal line at y = -5. You are really saying that for any value of x, y will equal -5.

There are an infinite number of solution sets to the function f(x) = -5. The x-y pairs are (-infinity, -5) ... (0, -5) ... (infinity, -5).

Answer 3

substitute y=-5 into the top equation to get: 5x-5=-5
so 5x=0 which means that y=0.

Answer 4

5x+y=-5
y=-5

Now, put y=-5 into first equation:
5x -5 = -5 so x = 0

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On your graph, sketch a line:
y = -5, this line is parallel to x-axis and cuts y-axis at y=-5

y = -5x-5

This line cuts x-axis at y=0, x= -1, it also cuts y-axis at x=0, y=-5

Answer 5

There is only one solution, the point (0,-5)