Use Pascal's triangle to find the coefficient of the third term in the expansion of (a + b)^2.
1 answer:
The pascal's triangle is formed by starting at 1 on the center, then expanding to the left and right as a pyramid by adding the two numbers on the diagonals directly above of the one you're calculating. A small Pascal's triangle can be seen below:
Since the term we have is squared, then we need to use the third row of the Pascal's triangle, which is "1 2 1", the third term is 1. The correct answer is D.
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The pairs of goldfish Tasha can buy for $20 are
Step-by-step explanation:
To find the how many type of goldfish that Tasha can buy for $20 is the set of positive ordered pairs.
Let x denote the number of fancy goldfish.
Let y denote the number of common goldfish.
To find how much goldfish can Tasha buy for $20 is to substitute the value for x in the equation
Now, substituting in
, we get,
The ordered pair is
Similarly, substituting ,
For ,
For ,
For ,
For ,
For ,
Thus, the pairs of goldfish Tasha can buy for $20 are