8th Grade Algebra: Answer Check #2
posted by Joy .
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^23x5) Answer: 12x^2
8.(3b+5)(b3) Answer: 3b^24b15
9.(6a^22)(a^21) Answer: 2a^2+2
10. (3p2)(3p+2) Answer: 9p^24
11. (3x^2+4)(3x^24) Answer:9x^216
12. (x9)^2 Answer: x^218x+81
13. (4x+3)(4x3) Answer: 16x^29
14. (3x^22x)^2 Answer: 3x^2+4x
If I got any wrong, can someone please show me how to do them correctly?

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^23x5) just expand
= 12x^4 + 9x^3 + 15x^2
#9
(6a^22)(a^21)
= 6a^4  6a^2  2a^2 + 2
= 6a^4  8a^2 + 2
#14
(3x^22x)^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