Is x/m(m^2 + n^2 + k^2) = xm + yn + zk? (1) z/k = x/m (2)

Question

Is x/m(m^2 + n^2 + k^2) = xm + yn + zk? (1) z/k = x/m (2) x/m = y/n OPEN DISCUSSION OF THIS QUESTION IS HERE: is-x-m-m-2-n-2-k-2-xm-yn-zk-99423.html

conocieur · Answer

I think is C

x/m(m^2 + n^2 + z^2) = xm + yn + zk

that is equal to

xm + xn^2/m + xz^2/n = xm + yn + zk

from I: x/m = y/n then xn = ym and from there (xn*n)/m is equal to 
ym*n/m equal to yn

so insuff

from ii, do the same stuff as i and you get zk

so insuff

taking both it works so C

ValleyBall1 · Answer

Right again - OA is C.

Study1 · Answer

Is x/m(m^2 + n^2+ k^2) = xm + yn + zk?

xm^2 + xn^2 + xk^2 = xmm +ynm +zkm?

Is xn^2 + xk^2 = ynm + zkm?

(1) z/k = x/m (xk = mz)

xk^2 = (xk)k = (mzk)

xn^2 + xk^2 = ynm + zkm =

xn^2 = ynm?
xn = my?

(2) x/m = y/n (xn = my)

xn^2 = (xn)n = (my)n

xn^2 + xk^2 = ynm + zkm =

xk^2 = zkm?
xk = mz?

Put (1) and (2) together

xn^2 + xk^2 = ynm + zkm =

(my)n + (mz)k = ynm + zkm

Both statements used = Answer C

Posted from my mobile device

BDSunDevil · Answer

is xm^2+xn^2+xk^2=xm^2+ynm+zkm
i. e. xn^2+xk^2=ynm+zkm
statement 1: xk=zm
 xn^2=ynm Not Sufficient
Statement 2: ym=xn
 xk^2=zkm Not Sufficient
Together: xn^2+xk^2=xn^2+xk^2
Sufficient

Bunuel · Answer

Is \frac{x}{m}*(m^2+n^2+k^2)=xm+yn+zk ? Multiply both part by m , to get rid of fraction part and open the brackets: is xm^2+xn^2+xk^2=xm^2+ynm+zkm ? xm^2 will cancel out and the question becomes: is xn^2+xk^2=ynm+zkm ? (1) \frac{z}{k}=\frac{x}{m} --> zm=kx --> substitute zm with kx --> is xn^2+xk^2=ynm+xk^2 --> xk^2 will cancel out and the question becomes is " xn^2=ynm ?" Not sufficient. (2) \frac{x}{m}=\frac{y}{n} --> xn=ym --> substitute ym with xn --> is xn^2+xk^2=xn^2+zkm --> xn^2 will cancel out and the question becomes "is xk^2=zkm ?" Not sufficient. (1)+(2) is xn^2+xk^2=ynm+zkm ? --> substitutein from (1) and (2) --> is xn^2+xk^2=xn^2+xk^2 ? Answer is YES. Sufficient. Answer: C. OPEN DISCUSSION OF THIS QUESTION IS HERE: is-x-m-m-2-n-2-k-2-xm-yn-zk-99423.html

Is x/m(m^2 + n^2 + k^2) = xm + yn + zk? (1) z/k = x/m (2)

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards