How do you solve #9x + 5y = 28# and #5x + 9y = 56#?

1 Answer
Jan 26, 2017

Answer:

#x=-1/2; y=13/2#

Explanation:

This can be solved by elimination method. To do this, one can try eliminating x, by multiplying the first equation by 5 and the second equation by 9, then subtracting as follows:
1st eq becomes 45x +25y = 140
2nd eq becomes45x +81y= 504

On subtracting, -56y = -364

Hence y=#364/56 = 13/2#

Using this value of y in the first equation, #9x +5(13/2)=28#

#9x= 28- 65/2#
Or, #9x= -9/2 -> x= -1/2#