GRE
The number of prime numbers between 4 and 15
The number of prime numbers between 16 and 30
a+b
4-(c+d)
The number of 20-pound boxes in the shipment
8
$$\frac{k}{m+4}$$
2(m-4)
|$$b^{2}+a$$|
|$$a-b^{2}$$|
q
s
|a|
|b|
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