Algebra Points: Solve the system by graphing?

Question

x-y= -13
-2x+y=8

The answer must be in a form similar to: (#, #) for example (–2, –5) OR (7, –3) BUT neither examples is the correct answer for this particular problem I was just giving a form example

CORRECTION: THE PROBLEM IS:
x+y= -13
-2x+y=8

Answer 1

ok this is wat u do

take -2x+y=8 and add -2x to both sides giving u y=8+2x

plug y into the first formula

that shud give u x

than plug x into either formula

and that will give u y

Im going to guess u r 14 or 15 cuz i did that as a freshman and i am now a junior...am i right?


O0O0O0 i just notice u have to graph it

ok u have y=x-13 and y= -2x +8

graph it and find where they intersect

Answer 2

By solving both equations for X you get:
x = y - 13 and x = (y/2) - 4

Therefore: y-13 = (y/2) - 4

Solve for Y and you end up with:
y = 18

Plug 18 into either equation and solve for x and you get:
x = 5

Therefore, the answer is (5,18)

edit: Errr ... yeah, forgot about the graph thing. However .. the only reason I would ever graph that out to find a solution would be for homework ... any other time I would just figure it out the way I did.

Answer 3

ok.. first.. you should change the form of the equation to be slope intercept form.. or.. y = mx + b

for x-y = - 13.... you get y = x + 13... slope of 1 and y-intercept of 13.

for -2x + y = 8... you get y = 2x +8... slope of 2 and y-intercept of 8.


ok.. now... where do these two meet?... substitue one of them into the other equation for y

y = x + 13 = 2x +8 is the point where they meet.. or..

just x+13 = 2x +8... and solve for x

2x - x = 13 - 8 ==> x = 5
now plug this into one of the equations to get y at that point...

y = 5 + 13 ==> y = 18
check it in the other equation.. substitute in both values...

18 = 2(5) + 8 ==> 18 = 10 + 8 ==> 18 = 18

so you have (5,18) algebraically.. but you need to plot the graphs and see that they really DO cross at this point and no other.

Answer 4

To solve by graphing, plug in an X variable and solve for Y about 3 times for each equation. Then fully draw out the lines, wherever they meet is the solution. The solution to your problem is (5, 18)

Answer 5

the following you want to remedy for y & put in kind y=mx+b. the position m is volume in the front of x & b is the volume by using itself. once you remedy for both one among those adult men you get y=-x-13 & y=2x+8; because you want to remedy by using graphing. b is the position the line hits the y axis and m is slope ( slope is upward thrust over run so 2 is up 2 over a million) graph both strains and the point the position they hit will be answer.

Answer 6

y=-x-13 y=2x+8

then just plug in the equations into the y= function on the calculator (upper left hand corner of Ti-80 or higher) and where they intersect is the answer
(-7,-6) i think

Answer 7

the answer is (-7,-6) n don mind me if i ask..but r u makin us do ur hw by any chance?