Correct except that you have lost a factor of 3 in no.3 Should be 3(2b+3)^2
Factor completely:
1. 5k^{3}- 40
5(k-2)(k^{2} + 2k + 4)
2. t^{2} - 81/169
(t + 9/13)(t - 9/13)
3. 12b^{2}+ 36b + 27
(2b+3)2
4. b^{4}- 16
(b^{2} +4)(b+2)(b-2)
82. (2k-7)h^{2 }- 4 (2k-7)h-45(2k-7)
(2k-7)(h+5)(h-9)
Thank you
Yes, that is correct.
Yes, that is correct.2. t^{2} - 81/169
(t + 9/13)(t - 9/13)
No, that is not correct. What you have written is the same as 2(2b+ 3)= 4b+ 6 (multiplication is commutative). What I think you meant was3. 12b^{2}+ 36b + 27
(2b+3)2
(2b+ 3)^{2} but that is still incorrect. (2b+ 3)^{2}= (2b)^{2}+ 2(2b)(3)+ 3^{2}= 4b^{2}+ 12b+ 9. Did you leave out a "3" that you factored out first? 12b^{2}+36b+ 27= 3(4b^{2}+ 12b^{2}+ 9)= 3(2b+ 3)^{2}.
Yes, this is correct.4. b^{4}- 16
(b^{2} +4)(b+2)(b-2)
Yes, that is correct.82. (2k-7)h^{2 }- 4 (2k-7)h-45(2k-7)
(2k-7)(h+5)(h-9)
Thank you