# Homework Help: Simulataneous equation with surds

1. Oct 6, 2007

### david18

Im trying a question from one of my text books which asks me to solve simultaneously:

5x-3y = 41 and (7√2)x + (4√2)y = 82

Ive tried elimination and substitute methods but the surds confuse me so i would appreciate it if anyone can come up with some guidelines of how i should approach this question.

thanks

2. Oct 6, 2007

### D H

Staff Emeritus
There is nothing special about the surds. Two suggestions if they confuse you:
• Replace the coefficients $7\surd2$ and $4\surd2$ with named parameters such as a and b. Solve and then replace a and b with the known values.
• Multiply both sides of the second equation by $\surd2$.

3. Oct 6, 2007

### HallsofIvy

Numbers are numbers! Just go ahead and solve the equations the way you would if there were no "surds". For example, you could multiply the second equation by 3 and multiply the first equation by 4$\sqrt{2}$, then add the equations to eliminate y.