Question

Can someone check my answers?

1. Simplify the sum or difference.
sqrt 5 + 6 sqrt 5
A) 6 sqrt 5
B) 30
C) 6 sqrt 10
D) 7 sqrt 5

2. Simplify the sum or difference.
4 sqrt 2 - 7 sqrt 2
A) negative sqrt 6
B) -3 sqrt 2
C) -11 sqrt 2
D) 11 sqrt 2

3. Simplify the sum or difference.
3 sqrt 7 - sqrt 63
A) -2 sqrt 7
B) -6 sqrt 7
C) -4 sqrt 3
D) 0

4. Simplify the sum or difference.
-6 sqrt 10 + 5 sqrt 90
A) 9 sqrt 10
B) -9 sqrt 10
C) -39 sqrt 10
D) -10

5. Simplify the product.
sqrt 6 (sqrt 2 + sqrt 3)
A) sqrt 8 + 3
B) sqrt 30
C) 2 sqrt 3 + 3 sqrt 2
D) 4 sqrt 2 + 3

Answer 1

1 - D

2 - B

3 - D

4 - A

5 - C

6 - A

7 - D

8 - B

9 - B

10 - C

i just took the "Operations with Radical Expressions practice" for WA connexus, these answers are 100 percent correct

Answer 2

1. sqrt5 + 6sqrt5 = (1+6)sqrt5 = 7sqrt5 (answer is D)
2. 4sqrt2 - 7sqrt2 = (4-7)sqrt5 = -3sqrt2 (answer is B)
3. 3sqrt7 - sqrt63 = 3sqrt7 - sqrt7 * sqrt9 = 3sqrt7 - 3sqrt7 = 0 (answer is D)
4. -6sqrt10 + 5sqrt90 = -6sqrt10 + 5*(sqrt10 * sqrt9) = -6sqrt10 + 5*(3sqrt10)
= -6sqrt10 + 15sqrt10 = 9sqrt10 (answer is A)
5. sqrt6*(sqrt 2 + sqrt 3) = sqrt12 + sqrt18 = 2sqrt3 + 3sqrt2 (answer is D)