43.5k views
20 votes
( – 1, – 5) 7x+2y=13, 4x+4y=14

1 Answer

3 votes

Answer:

{x,y} = {6/5,23/10}

Explanation:

[1] 7x + 2y = 13

[2] 4x + 4y = 14 <---------- linear equations given

Graphic Representation of the Equations : PICTURE
2y + 7x = 13 4y + 4x = 14

Solve by Substitution :

// Solve equation [2] for the variable y

[2] 4y = -4x + 14

[2] y = -x + 7/2

// Plug this in for variable y in equation [1]

[1] 7x + 2•(-x +7/2) = 13

[1] 5x = 6

// Solve equation [1] for the variable x

[1] 5x = 6

[1] x = 6/5

// By now we know this much :

x = 6/5

y = -x+7/2

// Use the x value to solve for y

y = -(6/5)+7/2 = 23/10

// Plug this in for variable y in equation [1]

[1] 7x + 2•(-x +7/2) = 13

[1] 5x = 6

// Solve equation [1] for the variable x

[1] 5x = 6

[1] x = 6/5

// By now we know this much :

x = 6/5

y = -x+7/2

// Use the x value to solve for y

y = -(6/5)+7/2 = 23/10

( – 1, – 5) 7x+2y=13, 4x+4y=14-example-1
User TomSawyer
by
6.4k points