Polynomial Expressions SI please help??

Question

anonymous · Answer

attachment

anonymous · Answer

Usually really easy but this one confuses me, if anyone could explain that would be great :)

anonymous · Answer

well do you know how to expand it?

anonymous · Answer

Distribute it? All I can get is 16x squared and I'm not sure of the rest

anonymous · Answer

I know a +121 is at the end

anonymous · Answer

hmm. try writing it out like this$$\left( 4x -11\right) * \left( 4x -11\right)$$

anonymous · Answer

so you got the first part.
16x ^2

anonymous · Answer

then multiply 4x^2 by -11

anonymous · Answer

ah that's so much easier!! Thank you. I've got 16x squared + 121, but how should I get the middle part if there is one

anonymous · Answer

okay so first multiply the terms |dw:1407874746013:dw|

anonymous · Answer

in step 1 and step2 and write them down

anonymous · Answer

16x squared and +121

campbell_st · Answer

this is a perfect square, 

$$(a - b)^2 = a^2 - 2ab + b^2$$

the middle term is double the product of the 2 terms in the binomial... 

$$2\times (-11 \times 4x) = $$

anonymous · Answer

@jnov  just use the formula that @campbell_st  wrote. pretend a is 4x^2 and b = -11