Hello :)
The first thing you want to do is use foil
F- first O- outer I-inner L-last
Lets start with F ( first)
6 × 3 = 18
Now, lets do O (outer)
6 × 2√10 = 12√10
<em>how to do it ?</em>
(6×2=12 and keep √10)
Then, we are going to do I ( inner)
(-√5) × 3= -3√5
<em>how to do it ?</em>
remove the parenthesis
-√5 × 3= -3√5
Lastly, we are going to do L (last)
(-√5) × 2 √10= -10√2
<em>how to do it ?</em>
remove the parenthesis from (-√5), then factor 2 √10
-√5 × 2
-√5 × 2 √5√2
there are two 5's so we use our radical rule √a√a=a
-2 × 5√2=-10√2
The last thing you have to do is put them all together
18+12√20-3√5-10√2
