Must graph x+y=3 and x-y=5 using y=mx+b and algebra to find the x and y. Please help I'm

**SSOOO**frustrated!
Tutors, please sign in to answer this question.

Olathe, KS

When an equation in first degree is given in the form y=mx+b then this can immediately be graphed with a slope of m and y intercept of b. A first degree equation is an equation that does not contain any variables raised to second power or greater.

The given equation is x+y=3. Subtract x from both sides. This will result in the equation below:

y=3-x

Rearranging the right side we can write the above equation as

y=-x+3

This equation is of the form y=mx+b (with m=-1 and b=3)

To graph this line, mark the first point at 3 on the y axis (b is 3 from above)

Since m, which is the slope, is -1, mark another point relative to this first point 1 unit to left and 1 unit up. We do this because the slope is -1 and a slope of -1 means 1 unit rise for -1 unit for run.

Join the two plotted points and extend in both ends to get the required line on the graph.

Do similar operations on x-y=5 as I explained for x+y=3. Perform operations on the given equation so that the equation transforms to y=mx+b form as follows:

x-y=5

subtracting y and 5 from both sides we get

x-5 = y or y=x-5

This can also be written as y=1*x-5

This is now in the form y=mx+b where m=1 and b=-5

Now mark the point -5 on the y axis. Mark another point 1 unit to the right and 1 unit up from this first point.

Join the two points and extend in both directions to get the required graph

x-y=5

subtracting y and 5 from both sides we get

x-5 = y or y=x-5

This can also be written as y=1*x-5

This is now in the form y=mx+b where m=1 and b=-5

Now mark the point -5 on the y axis. Mark another point 1 unit to the right and 1 unit up from this first point.

Join the two points and extend in both directions to get the required graph

The line for x+y=3 and x-y=5 will intersect at some point. Note the x and y coordinates at this point of intersection. This is the ordered pair for the required solution.

John K.

Ardent Mathematics, Science, History, SAT and German Polymath

College Point, NY

5.0
(50 ratings)

John E.

Physics and Math tutor - Masters from Cornell and Columbia University

New York, NY

4.8
(124 ratings)

Wesley L.

Premier MIT Math Tutor and SHSAT/SAT/ACT Specialist

New York, NY

5.0
(199 ratings)

- Triangles 146
- Algebra 1 3047
- Quadrilateral 16
- Math 6766
- Algebra 2 2689
- Prealgebra 141
- Trigonometry 1131
- Precalculus 1206
- ANGLES 81
- Geometry Word Problems 396

Find a tutor fast. Get the app.

Are you a tutor? Get the app for tutors

© 2005 - 2016 WyzAnt, Inc. - All Rights Reserved

## Comments