Factor the expression. 9b2 – 25
2 answers:
Answer: (3b + 5)(3b - 5)
Because both terms, 9b² and 25, are perfect squares, you can factor by taking the square roots of both terms.
The square root of 9b² is 3b (3b × 3b = 9b²).
The square root of 25 is 5 (5 × 5 = 25).
9b² - 25 has a negative, so the factored expression would be
(3b + 5)(3b - 5). The signs (+ and -) alternate in this case because the expression, 9b² - 25, has no middle term.
You can check your work by using FOIL. See the attachment below.
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Step-by-step explanation:
The window consists of a large square and 4 smaller triangles on the outside. The side length of this square is marked as 10, and therefore the area of this square is .
The area of a triangle is given by . Since the problem states that the overlapping squares are congruent, both legs of the triangle will be
and intersect at a
angle.
Thus, the sum of all four triangles is .
Therefore, the area of the window is: