Question

Expand (multiply) the following polynomial: (x + 3)2(x + 4) + (x + 3)3

Answer 1

\[ (x + 3)^2(x + 4) + (x + 3)^3\]

Answer 2

k use foil on the first 2, then add the resulting answer and the final brackets...?

Answer 3

(x + 3)2(x + 4)
(x + 3)(x + 3)(x + 4)

(x + 3)(x + 3) = x^2 + 3x + 3x + 9
(x^2 + 6x + 9)(x + 4)
x^3 + 6x^2 + 9x + 4x^2 + 24x + 36
add to final bracket

Answer 4

but where does the (x+3)^3 go?

Answer 5

(x + 3)3
expand this out using foil...
add to other brackets <x^3 + 6x^2 + 9x + 4x^2 + 24x + 36>

Answer 6

yeah but the solution here...

Answer 7

where?

Answer 8

(x+ 3)2(x + 4) + (x + 3)3 =
(x + 3)2[(x + 4) + (x + 3)] =
(x + 3)2[x + 4 + x + 3] =
x2 + 6x + 9(2x + 7) =
x2(2x + 7) + 6x(2x + 7) + 9(2x + 7) =
x2(2x) + x2(7) + 6x(2x) + 6x(7) + 9(2x) + 9(7) =
2x3 + 7x2 + 12x2 + 42x + 18x + 63 =
2x3 + 19x2 + 60x + 63

Answer 9

I don't understand this part

(x+ 3)^2(x + 4) + (x + 3)^3 =
(x + 3)^2[(x + 4) + (x + 3)] =

where does the root 3 go?

Answer 10

(x + 3)2(x + 4)
(x + 3)(x + 3)(x + 4)

(x + 3)(x + 3) = x^2 + 3x + 3x + 9

so
(x^2 + 6x + 9)(x + 4)
x^3 + 6x^2 + 9x + 4x^2 + 24x + 36

now (x+3)^3
(x+3)^3 = (x+3)(x+3)(x+3)
= (x^2 + 3x + 3x + 9)(x+3)
= (x^3 + 6x^2 + 9x + 3x^2 + 18x + 27

final answer =
x^3 + 6x^2 + 9x + 4x^2 + 24x + 36 + x^3 + 6x^2 + 9x + 3x^2 + 18x + 27
= 2x^3 + 12x^2 + 18x + 7x^2 + 42x + 63
= 2x^3 + 19x^2 + 60x + 63

... i think...?

Answer 11

yeah that doesnt make sense to me about the rt 3, sorry ???

Answer 12

yeah... it says the answer is

2x^3 + 19x^2 + 60x + 63

Answer 13

so yeah idk what their talking about with the root 3 but you got the answer the way I calculated mine so I guess it doesn't matter...

Answer 14

sweet, coz im totes lost h=there hey , sorry

Answer 15

No its cool, thanks for the help.