Add or Subtract (Radicals)

{ this means squared

1.3{2 + 4{2 Answer: 7{2

2. 8{3 + 3{3 Answer: 11{3

3. 7{5 - 3{5 Answer: 4{5

4. 8{2 - 5{2 Answer: 3{2

5. 6{x + 7{x Answer: 13{x

6. 9{y + 3{y Answer: 12{y

Multiply

7. -3x^2(4x^2-3x-5) Answer: 12x^2

8.(3b+5)(b-3) Answer: 3b^2-4b-15

9.(6a^2-2)(a^2-1) Answer: -2a^2+2

10. (3p-2)(3p+2) Answer: 9p^2-4

11. (3x^2+4)(3x^2-4) Answer:9x^2-16

12. (x-9)^2 Answer: x^2-18x+81

13. (4x+3)(4x-3) Answer: 16x^2-9

14. (3x^2-2x)^2 Answer: -3x^2+4x

If I got any wrong, can someone please show me how to do them correctly?

6 answers

check # 7,9,14

#7 is way off, there should have been 3 terms.

do those again.
I am really lost on all of those 3 problems.

Help please?
#7
-3x^2(4x^2-3x-5) just expand
= -12x^4 + 9x^3 + 15x^2

#9
(6a^2-2)(a^2-1)
= 6a^4 - 6a^2 - 2a^2 + 2
= 6a^4 - 8a^2 + 2

#14

(3x^2-2x)^2
= (3x^2 - 2x)(3x^2 - 2x)
= 9x^4 - 6x^3 - 6x^3 + 4x^2
= 9x^4 - 12x^3 + 4x^2
OHHH now I get it!

thank you very much!
y=x2+-24
can u help me