Answer:
48: D ([tex]10u^3+4u^2-2u+10[/tex])
[tex]\left(4u^3+4u^2+2\right)+\left(6u^3-2u+8\right)[/tex]
Remove brackets:
[tex]4u^3+4u^2+2+6u^3-2u+8[/tex]
Group the similar terms together:
[tex]4u^3+6u^3+4u^2-2u+2+8[/tex]
Add/Subtract:
[tex]10u^3+4u^2-2u+10[/tex]
49: A. ([tex]2x\left(x^2+2x+4\right)[/tex])
[tex]2x^3+4x^2+8x[/tex]
Factor out 2x:
[tex]2x\left(x^2+2x+4\right)[/tex]
50: C. ([tex]8x^2+26x+15[/tex])
[tex]\left(4x+3\right)\left(2x+5\right)[/tex]
Use FOIL:
[tex]4x* \:2x+4x* \:5+3* \:2x+3* \:5[/tex]
[tex]8x^2+20x+6x+15[/tex]
[tex]8x^2+26x+15[/tex]
51: B. ([tex]8n^3+6n^2-4n-20[/tex])
[tex]\left(2n^2+4n+4\right)\left(4n-5\right)[/tex]
Expand:
[tex]2n^2* \:4n+2n^2\left(-5\right)+4n* \:4n+4n\left(-5\right)+4* \:4n+4\left(-5\right)[/tex]
[tex]8n^3-10n^2+16n^2-20n+16n-20[/tex]
[tex]8n^3+6n^2-20n+16n-20[/tex]
[tex]8n^3+6n^2-4n-20[/tex]
52: D. [tex](d+9)(d+1)[/tex]
You can factor by grouping:
[tex]d^2+10d+9[/tex]
[tex]\left(d^2+d\right)+\left(9d+9\right)[/tex]
[tex]d\left(d+1\right)+9\left(d+1\right)[/tex]
[tex](d+9)(d+1)[/tex]
