## anonymous 5 years ago √7(3-2√7)

1. anonymous

if you have a fraction with a sqrt on the denominator (bottom part). You have to multiply and devide your fraction by the same sqrt:$-2/\sqrt{7}$$(-2/\sqrt{7}) * (\sqrt{7}/\sqrt{7}) = (-2\sqrt{7} / 7)$

2. anonymous

parenthesis first:$(3-2\sqrt{7}/7) = (21-2\sqrt{7})/7$

3. anonymous

thx

4. anonymous

wait, i dont get it

5. anonymous

for last multiply:$\sqrt{7} * (21-2\sqrt{7})/7 = (21\sqrt{7}- 2*7) / 7 = (21\sqrt{7} - 14)/7$

6. anonymous

you can simplify by factoring 21 and 14:$[7*(3\sqrt{7}-2)]/7 = (3\sqrt{7}-2)$