If you wanted to write 4/10 as a decimal it would be .4
It's not the difference of squares, rather it is the square of a difference. That leaves a perfect square trinomial, which narrows your selection to two choices. An expression with 2 terms is not a trinomial, so that further narrows your selection. The appropriate choice is
... (4xy -3z)² = 16x²y² -24xyz +9z², a perfect square trinomial
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The expression you have in your problem statement has no z term, so none of the choices is applicable to that one.
In order to find out the answer , you just need to count :
Let's say that mary's collection is symbolized by x
2/3 x = 4h
x = 3/2 . 4h
x = 6h
The storybooks they have in total would be : 6h + 4h = 10 h
hope this helps
Range? that's a possibility
