SOLUTION: Find the x- and y-intercepts and graph the equation plotting the intercepts. Please show all of your work. 3x-6y= -21

Algebra ->  Linear-equations -> SOLUTION: Find the x- and y-intercepts and graph the equation plotting the intercepts. Please show all of your work. 3x-6y= -21      Log On


   

Question 476529: Find the x- and y-intercepts and graph the equation plotting the intercepts. Please show all of your work. 3x-6y= -21
Found 2 solutions by robertb, ccs2011:
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
Express the equation in intercept form x%2Fa+%2B+y%2Fb+=+1
Divide both sides by -21:
%283x%29%2F%28-21%29+%2B+%28-6y%29%2F%28-21%29+=+1
<==>x%2F%28-7%29+%2B+%282y%29%2F7+=+1
<==>x%2F%28-7%29+%2B+y%2F%287%2F2%29+=+1
Therefore the x-intercept is (-7,0), and the y-intercept is (0,7/2).

Answer by ccs2011(207) About Me  (Show Source):
You can put this solution on YOUR website!
3x+-+6y+=+-21
Easiest way to find intercepts is to set one variable equal to zero.
An intercept means point on the axis therefore either x or y must be zero.
For x-intercept, y=0.
For y-intercept, x =0.
Let y = 0. Solve for x.
3x+-+6%280%29+=+-21
3x+-+0+=+-21
3x+=+-21
x+=+-7
The x-intercept is the point (-7,0). x= -7, y = 0
Let x = 0. Solve for y.
3%280%29+-+6y+=+-21
0+-+6y+=+-21
-6y+=+-21
y+=+%28-21%29%2F-6+=+7%2F2+=+3.5
The y-intercept is the point (0,3.5). x= 0, y = 3.5
Now plot these 2 points and then draw a straight line through both points.
This line represents all possible points that satisfy the equation 3x+-+6y+=+-21
here is what your graph should look like:
graph%28200%2C200%2C-10%2C6%2C-2%2C6%2C0.5x%2B3.5%29