SOLUTION: What is the correct answer to the problem see below: x+y=12

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Question 126897: What is the correct answer to the problem see below:
x+y=12
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

x%2By=12
if you want to solve for x, it will be:
x=+-y+%2B+12

if you want to solve for y, it will be:

y+=+-x%2B+12
if you want to graph it, here is the graph of x%2By=12
:

Solved by pluggable solver: Graphing Linear Equations


1%2Ax%2B1%2Ay=12Start with the given equation



1%2Ay=12-1%2Ax Subtract 1%2Ax from both sides

y=%281%29%2812-1%2Ax%29 Multiply both sides by 1

y=%281%29%2812%29-%281%29%281%29x%29 Distribute 1

y=12-%281%29x Multiply

y=-1%2Ax%2B12 Rearrange the terms

y=-1%2Ax%2B12 Reduce any fractions

So the equation is now in slope-intercept form (y=mx%2Bb) where m=-1 (the slope) and b=12 (the y-intercept)

So to graph this equation lets plug in some points

Plug in x=3

y=-1%2A%283%29%2B12

y=-3%2B12 Multiply

y=9 Add

So here's one point (3,9)





Now lets find another point

Plug in x=4

y=-1%2A%284%29%2B12

y=-4%2B12 Multiply

y=8 Add

So here's another point (4,8). Add this to our graph





Now draw a line through these points

So this is the graph of y=-1%2Ax%2B12 through the points (3,9) and (4,8)


So from the graph we can see that the slope is -1%2F1 (which tells us that in order to go from point to point we have to start at one point and go down -1 units and to the right 1 units to get to the next point), the y-intercept is (0,12)and the x-intercept is (12,0) . So all of this information verifies our graph.


We could graph this equation another way. Since b=12 this tells us that the y-intercept (the point where the graph intersects with the y-axis) is (0,12).


So we have one point (0,12)






Now since the slope is -1%2F1, this means that in order to go from point to point we can use the slope to do so. So starting at (0,12), we can go down 1 units


and to the right 1 units to get to our next point



Now draw a line through those points to graph y=-1%2Ax%2B12


So this is the graph of y=-1%2Ax%2B12 through the points (0,12) and (1,11)