Answer:
A. 9A² - 16B²
Step-by-step explanation:
(3A + 4B)(3A - 4B)
Distribute:
3A(3A - 4B)
4B(3A - 4B)
Multiply:
3A(3A - 4B)
3A(3A) + 3A(-4B)
9A² - 12AB
4B(3A - 4B)
4B(3A) + 4B(-4B)
12AB - 16B²
Combine like terms:
9A² - 12AB + 12AB - 16B² <== -12AB + 12AB cancels out
9A² - 16B²
Therefore, our final answer is 9A² - 16B²
Hope this helps!
Answer:
cosB = 21/75, tanB = 72/21
Step-by-step explanation:
Here, we can use pythagoras to figure out all sides. 75^2-72^2 = 21^2. So, we have sides with lengths 21, 72, and 75. We are given that sinB = 72/75. The definition of sin is opposite of hypotenuse. So, the opposite of angle B is side CA and the hypotenuse is BA. This allows us to find that BC is the 21 length side. The cos of an angle is adjacent over hypotenuse. In this case, it is BC/BA which is 21/75. similarly, Tan is opposite over adjacent or 72/21. And we are done. Those are the values. TO remember these, use the acronym:
SOH CAH TOA. S refers to sin and OH refers to opposite over hypotenuse. Similarly C is cos, A is adjacent, and H is hypotenuse, and then T is tan, o is opposite and A is adjacent.
%55? mot sure so do NOT count on me im only a sixth grader
Step-by-step explanation:
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