Doing an SAT practice test and came across this question: "Which of the following is equivalent to [math]\frac{3b^2+9b}{3b+6}[/math] A ) [math]b-\frac{6}{3b}[/math] B ) [math]b[/math] C ) [math]b+1-\frac{6}{3b+6}[/math] D ) [math]b+3[/math]"
I got frustrated and used a calculator even tho it is on the no-calculator section, and to my confusion the answer is C. My attempts at reducing it: [math]\frac{3b^2+9b}{3b+6} = \frac{b^2+3b}{b+2} = [/math]??? Can somebody explain this to my babby brain? How can I arrive at the answer C?
This, Red will never learn how to factor neither squares nor women
Parker Brooks
you got this from the 2017 sat princeton prep book or a site that stole from it the answer to this question is incorrect t. tutored out of the book during the summer
there you can go to bed now
Easton King
thanks, he's a little bit slow in the head; so now he can rest well.
James Stewart
no problem. glad to help ;)
Ian Young
what? the answer [math]\frac{3b^2+9b}{3b+6} [/math] is the same as [math]\frac{3b^2+6b+3b}{3b+6} [/math] which is [math] \frac{b(3b+6)+3b} {3b+6} [/math] or [math] b+ \frac{3b}{3b+6} [/math] and you can add zero as [math] \frac{6}{3b+6}-\frac{6}{3b+6} [/math] or [math] b+ \frac{3b}{3b+6}+\frac{6}{3b+6}-\frac{6}{3b+6} [/math] which gets you [math] b+ \frac{3b+6}{3b+6}-\frac{6}{3b+6} [/math] for a final answer of [math] b+ 1-\frac{6}{3b+6} [/math] C
Evan King
You can brute force this in about 10 seconds by choosing an easy number like [eqn]b=1[/eqn] and seeing that the only one the original expression is equal to is C.
Putting b = 0 we get 0. So it must be B or C. But it is easy to see that it is not B, so it must be C.
Levi Clark
Is there a name for this method? I never seen it before.
Blake Wright
Why not use partial fraction decomposition
Cameron Evans
Your dick.
Logan Phillips
Still not clear on how you get from [math]\frac{b(3b+6)=3b}{3b+6}[/math] to [math]b+\frac{3b}{3b+6}[/math] Can you explain a little more pls, I am slow.
Joshua Davis
[math]\frac{b(3b+6)+3b}{3b+6}[/math] to [math]b+\frac{3b}{3b+6}[/math] rather.
John Nguyen
This is fucked, my tex is correct. Well you get what I'm saying.
If the answer method will take too long a time, refrain from it and try thinking of a faster method. Since we are comparing the four choices to a single fraction, try writing the choices as a fraction and eliminate what are not possible or probable. "B" is the easiest it will be [math]\frac{b}{1} then it is not the answer and we eliminate it. "A" as a single fraction will be [math]\frac{3b^2-6}{3b} this is also not the answer and we eliminate A. "D" will also be eliminated and "C" will be the only answer left and most probable.
Jacob Rogers
You can factor out a 3 and do synthetic division leaving you with b + 1 + (-2/(b+2)). Then, put multiply that last term by 3/3 and you get the previous with -6/(3b+6). Then you inject yourself with ketamine to forget that you don't know beta-tier math.
Samuel Nelson
>tutored out of the book this summer wow, you were getting paid to teach people wrong?