MATH SOLVE

2 months ago

Q:
# Pilar says that two linear systems below have the same solution. (see picture) Is she correct? Explain.

Accepted Solution

A:

The first set:

3x + 2y = 2 ---1)

5x + 4y = 6 ---2)

From 1), multiply all by 2, 6x + 4y = 4 ---3)

3) - 2),

6x + 4y - (5x + 4y) = 6 - 4

6x + 4y - 5x - 4y = 2

x = 2

Sub in x = 2 into 1),

3(2) + 2y = 2

2y = -4

y = -2

(2 , -2)

The second set:

3x + 2y = 2 ---1)

11x + 8y = 10 ---2)

From 1), multiply all by 4, 12x + 8y = 8 ---3)

3) - 2),

12x + 8y - (11x + 8y) = 8 - 10

12x + 8y - 11x - 8y = -2

x = -2

From this x value alone, we can tell that these two linear systems do NOT have the same solution as they meet at different coordinates.

Hope this helped! Ask me if there's any working from here that you don't understand! :)

3x + 2y = 2 ---1)

5x + 4y = 6 ---2)

From 1), multiply all by 2, 6x + 4y = 4 ---3)

3) - 2),

6x + 4y - (5x + 4y) = 6 - 4

6x + 4y - 5x - 4y = 2

x = 2

Sub in x = 2 into 1),

3(2) + 2y = 2

2y = -4

y = -2

(2 , -2)

The second set:

3x + 2y = 2 ---1)

11x + 8y = 10 ---2)

From 1), multiply all by 4, 12x + 8y = 8 ---3)

3) - 2),

12x + 8y - (11x + 8y) = 8 - 10

12x + 8y - 11x - 8y = -2

x = -2

From this x value alone, we can tell that these two linear systems do NOT have the same solution as they meet at different coordinates.

Hope this helped! Ask me if there's any working from here that you don't understand! :)