Thread: simultaneous equations!!

please i need help with the processes of these two simultaneous equations!!:

7x + 2y = -4
3x + 4y = 14

and...

x/2 + y/3 = 5
x/3 + y/4 = 1

Originally Posted by lauqui

please i need help with the processes of these two simultaneous equations!!:

7x + 2y = -4
3x + 4y = 14

...(1)
...(2)

Working with (1)







Now sub this into (2)





Can you find x now?

Originally Posted by lauqui

x/2 + y/3 = 5
x/3 + y/4 = 1

Use the same process as in my first post.

...(1)

...(2)

Working on (1)







Now into (2)



You can take it from here....

Once you have a solution for x substittue this into either (1) or (2) to find y.

Originally Posted by lauqui

7x + 2y = -4 [1]
3x + 4y = 14 [2]

This is another way, known as the "elimination" process:

Multiply [1] by -2:
-14x - 4y = 8
3x + 4y = 14 [2]

Add them up:
-11x = 22
x = -2 ; next get y by substituting.

Just so you have a headstart on your teacher !