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Question 206571: Graph the equation and identify the y-incercept.
How do I solve y+x=-7. Type and ordered pair.
I do not understand. I have read and re-read the material and am not having alot of success.
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! your equation is y + x = -7
you need to solve for y
subtract x from both sides of the equation to get y = -7 - x
this is the same as y = - x - 7
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the y intercept is the value of y when x = 0
if you make x = 0 your equation should be y = - 7 which makes your y intercept -7
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the standard form of a linear equation in 2 dimensions is y = mx + b where m is the slope and b is the y intercept.
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it looks like your equation is already in the standard form after you solved for y.
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your equation is y = -x - 7
your slope must be -1.
this make m = -1
your y intercept is -7.
this makes b = -7.
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an ordered pair would be (x,y) which means an x value and a y value on the graph of your equation.
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one point on your graph would be:
let y = 0
your equation becomes 0 = - x - 7
solve for x and you get x = -7
so when y = 0, x = -7 meaning the ordered pair would be (x,y) = (-7,0)
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another point on your graph would be:
let x = 0
your equation becomes y = - 7
y is already solveed for.
so when x = 0, y = -7 meaning the ordered pair would be (x,y) = (0,-7)
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to find any (x,y) ordered pair on your equation, simply pick a value of x in the domain and solve for y.
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your domain is all real number because there is no restriction to make it otherwise. you don't have any square roots of negative numbers nor do you have any value of x that are in the denominator making division by 0 a possibility. both of these would not be allowed in the domain (no square roots of negative numbers and no divisions by 0).
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so pick any value of x ande solve for y.
take x = -10
your equation is y = -x -7
when x = -10 this equation becomes y = - (-10) - 7
this becomes y = + 10 - 7 which becomes y = 3
your ordered pair would be (x,y) = (-10,3)
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now we'll graph your equation and see how we did.
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the graph of your equation is the slanted line.
the vertical line at x = -10 and the horizontal line at y = 3 are just there to show you the value of y when x = -10 better. that would be the intersection of the graph of your equation with those vertical and horizontal lins.
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