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by Brent@GMATPrepNow » Mon Jul 29, 2013 8:30 pm
ashblog02 wrote:I am solving prob 4 on pg 933 in kaplan gmat 2014 book -I have a basic maths qs
Is 2 + 2^3 = 4^3 or you cant simplify this 2+2^3 any further?

To test whether 2 + 2^3 = 4^3, evaluate both sides. We get . . .
2 + 8 = 64
10 = 64 . . . NOPE

We can't really do much to simplify 2 + 2^3, especially since this evaluates to be a small number (10).
Of course, you could factor to get:
2 + 2^3 = 2(1 + 2^2)
= 2(1 + 4)
= 2(5)
= 10

I hope that helps.

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by [email protected] » Tue Jul 30, 2013 4:03 pm
Hi ashblog02,

One of the basic algebra rules that you were probably taught when you were younger is "combine LIKE terms"; this concept is tested repeatedly on the GMAT, but the rules are consistent, regardless of what the "terms" are.

For example:

2 + 3 = 5 similar terms means you can combine them

2 + x doesn't turn into anything else because the terms are different

y + 3y = 4y

5 cars + 7 cars = 12 cars

(root7) + (root7) = 2(root7)

Sometimes you can change what a term "looks like" and then combine it with another term:

For example:

(root2) + (root50) = (root2) + 5(root2) = 6(root2)

Keep an eye out for ways to combine like terms and simplify expressions; just remember though - they have to be LIKE terms.

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