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Hey
I believe on page 105, numbers 2 and 8 are just for demonstration, showing that in: √2 + √2 + √8, only √2 + √2 can be added and √8 is just carried over, which gives: 2√2 + √8. Think this way (like book shows): x + x + y = 2x + y; this is because you can combine like terms.
As for Roots Drill #7: 3 √2 + 2 √8 + √32 Ok, you want to split as much as possible; 1) 3 √2 - cannot split, leave as is.
2) 2 √8 - √8 can be split into √4 * √2 - now √4 is =2; so √8 = 2√2. Therefore, 2√8 = 2 * 2√2 = 4√2
3) √32 - split this too: √4 * √4 * √2 - see that √4 = 2, therefore you get: 2 *2 * √2; OR = 4 √2
Now put together 1,2,and 3: 3 √2 + 4 √2 + 4 √2 = (3 + 4 + 4) * √2 = 11 √2
Does that help at all? You want to break; split each; then combine.
Thanks, Jay
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