While solving GMAT quant questions, always remember that your one goal is to identify the correct answer as efficiently as possible, and not to please your former math teachers.
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Comment on Operations with Roots
Sir in the related resources
The Khan Academy questions
The Khan Academy questions provided on the linked page are not 700+ questions. If 700+ level questions do exist on the GMAT, they are likely VERY RARE.
So, you might want to see what you can find on GMAT Club.
I need some help with this
Here's my step-by-step
Here's my step-by-step solution: https://gmatclub.com/forum/root-9-root-80-root-9-root-95570.html#p1891953
Thank you. Didn't see that
In the video you pointed out that if a root is divided, the number in front of the root is divided and the number inside the root is. But how is (9√5)/(3√15) = 3/√3 when 9/3 is 3 and 5/15 is not 3?
Thanks for the reply!
You're correct about the rule
You're correct about the rule.
In general we can say:
(w√x)/(y√z) = (w/y)(√(x/z))
So, 9/3 = 3
And √5/√15 = √(5/15) = √(1/3)
So, we get: (9√5)/(3√15) = 3√(1/3) which is the same as 3/√3
At this point, we can simplify 3/√3 by multiplying top and bottom by √3.
We get: (3√3)/3 which equals √3
Does that help?
Hey Brent, I see your
Algebraically, how would this look. I didn't see it the way you did and tried to mathematically solve it and kept getting 36. Maybe it's best I dont know lol but was curious as I was trying to take numbers out of the root sign
What question are you
What question are you referring to?
If you want to show your
If you want to show your solution, I can take a look.
I'm wondering if there is a
Question link: https:/
Question link: https://gmatclub.com/forum/root-9-root-80-root-9-root-79493.html
Aside from the strategies shown in the linked thread, the only other strategy I can think of is to use some estimation.
Estimation would help us eliminate 2 or 3 answer choices, but I think it would be pretty tricky to use straightforward rationale to justify why answer choice E (20) is a better estimate than answer choice D (18).
That said, on test day, if you're not sure what to do, estimation could help narrow your odds down to 50:50.
I don't understand why isn't
Question link: https:/
Question link: https://gmatclub.com/forum/which-of-the-following-is-equivalent-to-24206...
I'm not sure how you would arrive at B, since it would be tricky to eliminate all roots.
Are you okay with the rationale for choice D?
so if you square both side
If there were an equation
If there were an equation here, we could square both sides.
So, let's create the equation: x = (√21)/6, which means our goal is to find the value of x.
If we square both sides we get: x² = 21/36
Simplify to get: x² = 7/12
Now take the square root of both sides: √(x²) = √(7/12)
Simplify: x = √(7/12)
oh, i see what you meant,