## anonymous 5 years ago When adding and subtracting radicals, can you join like terms ignoring the signs

1. amistre64

??

2. anonymous

what do u mean by signs?

3. angela210793

what r radicals? O.o

4. anonymous

$2\sqrt{10}-3\sqrt{40}$

5. amistre64

when adding and subtracting radicals; the radicals act like a variable in that you can only work them out if they are the same...

6. amistre64

you have to rewrite sqrt(40) in terms of sqrt(10)s to work this out

7. amistre64

sqrt(40) = sqrt(10*4) = sqrt(10) sqrt(4) sqrt(10) [2 - 3(2)] = -4sqrt(10)

8. angela210793

2sqr10-3sqr(4*10)=2sqr10-6sqr10=-4sqr10.....i guess :)