/sci/ - Science & Math

[Anonymous No.2695675]

(sci) I need some help factoring these problems any way you can help, there pretty simple but im just learning it.

[Anonymous No.2695684]

25r^2+20r+4

[Anonymous No.2695685]

What problems.

[Anonymous No.2695689]

>>2695684
(5r+2)^2

[Anonymous No.2695704]

Next?

[Anonymous No.2695705]

75u^2-192w^2

Factor by substitution
3(x+5)^2+17(x+5)+22

64+c^3

Factor by grouping
402x-26y+13xy

[Anonymous No.2695712]

>>2695705
last one is 4-2x-26y+13xy

[Anonymous No.2695754]

>>2695705

><span class="math"> 75u^2-192w^2 [/spoiler]
<span class="math"> 3(5u-8w)(5u+8w) [/spoiler]

><span class="math"> 3(x+5)^2+17(x+5)+22 [/spoiler]
Let u=x+5
<span class="math"> 3u^2+17u+22 [/spoiler]
<span class="math"> (u+2)(3u+11) [/spoiler]
<span class="math"> (x+7)(3x+26) [/spoiler]

><span class="math"> 64+c^3 [/spoiler]
<span class="math"> (x+4)(x^2-4x+16) [/spoiler]

><span class="math"> 402x-26y+13xy [/spoiler]
<span class="math"> x(13y+402)-26y [/spoiler]

[Anonymous No.2695859]

>>2695705
>75u^2-192w^2
3(25u^2-64w^2)
3((5u)^2-(8w)^2)
I think.

>3(x+5)^2+17(x+5)+22
3(x^2+10x+25)+17x+85+22
3x^2+30x+75+17x+85+22
3x^2+47x+182 - Find a number pair that adds to middle term and multiplies to the product of the other two and split one of them into an amount of parts equal to the first term (in this case 3).
In this case, 26 and 21. 21/3=7
(3x+26)(x+7). This expands to what you want.

>64+c^3
4^3+c^3
Sum of two cubes
(c^2-cx+x^2)(c+x) Where c=4 in this case
(c^2-4x+16)(c+4)

>4-2x-26y+13xy
2(2-x)-13y(2-x)
2-13y

[Anonymous No.2695862]

remember that you can always check

http://www.wolframalpha.com/input/?i=Factor[25r^2%2B20r%2B4]

for results