MATH SOLVE

4 months ago

Q:
# Graph the linear equation. Find three points that solve the equation, then plot on the graph. -5x -3y = -7

Accepted Solution

A:

-5x - 3y = -7

-3y = 5x - 7

y = -5/3x + 7/3......so there is a slope of -5/3....and a y int of 7/3 (or 2 1/3)

the x int can be found by subbing in 0 for y and solving for x

0 = -5/3x + 7/3

5/3x = 7/3

x = 7/3 * 3/5

x = 7/5 (or 1 2/5)

so lets put this in standard form and find some points on ur line that are not fractions.

y = -5/3x + 7/3

5/3x + y = 7/3...multiply everything by 3

5x + 3y = 7....this is standard form

5x + 3y = 7.....subbing in 2 for x

5(2) + 3y = 7

10 + 3y = 7

3y = 7 - 10

3y = -3

y = -3/3

y = -1.......so one solution is (2,-1)

5x + 3y = 7....subbing in -1 for x

5(-1) + 3y = 7

-5 + 3y = 7

3y = 7 + 5

3y = 12

y = 12/3

y = 4.......so another point on ur line is (-1,4)

5x + 3y = 7....subbing in -4 for x

5(-4) + 3y = 7

-20 + 3y = 7

3y = 7 + 20

3y = 27

y = 27/3

y = 9 .....and another point on ur line is (-4,9)

another one is (3,-3)

thats gonna be all the even numbers that u will get on ur graph..

(2,-1), (-1,4), (-4,9) , (3,-3)

so to break it down, ur y int (where the line crosses the y axis) is at (0,7/3) or (0,2 1/3)........ur x int (where ur line crosses the x axis) is at (7/5,0) or

(1 2/5,0).....and then there are the points on ur line (2,-1),(-1,4),(-4,9), and (3,-3)

-3y = 5x - 7

y = -5/3x + 7/3......so there is a slope of -5/3....and a y int of 7/3 (or 2 1/3)

the x int can be found by subbing in 0 for y and solving for x

0 = -5/3x + 7/3

5/3x = 7/3

x = 7/3 * 3/5

x = 7/5 (or 1 2/5)

so lets put this in standard form and find some points on ur line that are not fractions.

y = -5/3x + 7/3

5/3x + y = 7/3...multiply everything by 3

5x + 3y = 7....this is standard form

5x + 3y = 7.....subbing in 2 for x

5(2) + 3y = 7

10 + 3y = 7

3y = 7 - 10

3y = -3

y = -3/3

y = -1.......so one solution is (2,-1)

5x + 3y = 7....subbing in -1 for x

5(-1) + 3y = 7

-5 + 3y = 7

3y = 7 + 5

3y = 12

y = 12/3

y = 4.......so another point on ur line is (-1,4)

5x + 3y = 7....subbing in -4 for x

5(-4) + 3y = 7

-20 + 3y = 7

3y = 7 + 20

3y = 27

y = 27/3

y = 9 .....and another point on ur line is (-4,9)

another one is (3,-3)

thats gonna be all the even numbers that u will get on ur graph..

(2,-1), (-1,4), (-4,9) , (3,-3)

so to break it down, ur y int (where the line crosses the y axis) is at (0,7/3) or (0,2 1/3)........ur x int (where ur line crosses the x axis) is at (7/5,0) or

(1 2/5,0).....and then there are the points on ur line (2,-1),(-1,4),(-4,9), and (3,-3)