## anonymous one year ago Need help with square root problem please :)

1. anonymous

|dw:1440383921670:dw|

2. anonymous

sorry if you cant read this. but i multiped 7 and 5 and got 35 multiplied 2 and 6 and got the square root of 12 and i multiplied 7 and 4 and got -28 and i tried multiplying 7 and the square root of 2 but it gives me 14 and everytime i try to simplify it doesnt make sense and doesnt give me the right answer.

3. anonymous

the answer is 70 and square root of 3 -56 but how is it 56?

4. anonymous

$70\sqrt{3}-56$ okay thats the answer

5. anonymous

Using the distributive property$7\sqrt{2}\left( 5\sqrt{6}-4\sqrt{2} \right)$$=35\sqrt{12} - 28\sqrt{4}$Does this help?

6. anonymous

but dont you multiply the 7 and the square root of 2?

7. anonymous

It helps, but im just wondering why i dont multiply it

8. anonymous

You're multiplying $$7\sqrt{2}$$ by $$4\sqrt{2}$$. You multiply the coefficients together and the radicals together to give $$28\sqrt{4}$$ which, of course, can be simplified.

9. anonymous

oh! okay i understand!! thank you so much. :)

10. anonymous

In general$a \sqrt{b} \times c \sqrt{d} = ac \sqrt{bd}$

11. anonymous

You're welcome

12. triciaal

|dw:1440384808581:dw|

13. triciaal

|dw:1440385345310:dw|

Find more explanations on OpenStudy