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

Jan 26, 2017

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=$\frac{364}{56} = \frac{13}{2}$

Using this value of y in the first equation, $9 x + 5 \left(\frac{13}{2}\right) = 28$

$9 x = 28 - \frac{65}{2}$
Or, $9 x = - \frac{9}{2} \to x = - \frac{1}{2}$