i need help with 16a^2-8az+z^2-9a^2

would this be the difference of squares because of the perfect square trinomial grouping ? but then i get stuck??

Question

i need help with 16a^2-8az+z^2-9a^2

would this be the difference of squares because of the perfect square trinomial grouping ? but then i get stuck??

jim_thompson5910 · Answer

show us what you have so far

jhannybean · Answer

groupp your terms together, maybe it'll make it easier to identify

anonymous · Answer

(4a-z)^2 - (9a)^2

(2a-z-3a)(2a-z+3a)

anonymous · Answer

or should i just group as 4 terms? but i dont think that works

jim_thompson5910 · Answer

9a^2 is NOT the same as (9a)^2

anonymous · Answer

*(9a^2)

jhannybean · Answer

$$\color{blue}{(16a^2-9a^2)}-8z^2-z^2$$

anonymous · Answer

ok i did that. let me try again

jhannybean · Answer

oop,$+z^2$

anonymous · Answer

but when i factor first part, it cancels out

anonymous · Answer

it doesnt work

jhannybean · Answer

thats the point, your simplifying your expression, not trying to find perfect squares and such.

anonymous · Answer

i have to factor completely

jhannybean · Answer

You will, just reduce the function first.

jim_thompson5910 · Answer

You should have this. You are very close to the answer

16a^2-8az+z^2-9a^2

(4a-z)^2-(3a)^2

(4a-z + 3a)(4a-z - 3a)

jim_thompson5910 · Answer

notice how the 4a-z doesn't change

anonymous · Answer

wait i dont know why i changed that to 2, sorry.  or took the square root. it should stay the same

anonymous · Answer

@jim_thompson5910  but doesnt 4a and 3a combine like terms?

anonymous · Answer

would i combine those?

jim_thompson5910 · Answer

yes it does, so you can simplify what I have further

anonymous · Answer

oh ok. i thought it was weird so that's why i asked for the answer.. thought i did something wrong

anonymous · Answer

ty

jhannybean · Answer

Bleh, way too long.