Question

Solve 5x + 2y = 7
10x + 4y = 14

a. (1, 1)

b. (2,-3/2 )

c. No Solution

d. Infinitely Many Solutions

Answer 1

5x + 2y = 7
10x + 4y = 14
--------------------
x = (7-2y)/5
-------------------
10x + 4y = 14
10(7-2y)/5 + 4y = 14

2(7-2y)+4y=14

14-4y+4y=14

14=14
-----------------
No solution

Answer 2

ahh the good old systems...

multiply the first equation by -2...

5(-2)x + 2(-2)y =7(-2)
10x + 4y = 14

-10x -4y = -14
10x + 4y = 14

do you see something odd? :DDD