Answer:
B
Step-by-step explanation:
If C is the correct answer and if the final result is multiplied out, where does the minus sign in a^4 - b^4 come from? All pluses don't make a minus. A is incorrect.
If D is correct, then a^2 - b^2 should be further factored producing a different kind of answer, like (a + b)^2(c-d)^2 which is not the same as a^4 - b^4. So D is not correct.
The first step in factoring a^4 - b^4 is (a^2 + b^2)(a^2 - b^2) A doesn't lead you anywhere. A is incorrect. The answer must be B.
a^4 - b^4 = (a^2 - b^2)(a^2 + b^2) The first term factors.
a4 - b^4 = (a + b)(a - b) (a^2 +b^2)
Answer:
about 14° south of east
Step-by-step explanation:
The river speed is about ...
(2.35 m/s)×(1 mi/(1609.344 m))×(3600 s)/(1 h) ≈ 5.2568 mi/h
The angle of interest is such that its sine is the ratio of river speed to boat speed:
sin(α) = (5.2568 mi/h)/(21.8 mi/h) = 0.241138
α = arcsin(0.241138) = 13.9537°
Since the river is flowing north, the boat should be directed south of its intended course by this angle.
The boat should be directed 14° south of east.
L = 2W
A = L * W
A = 162
162 = 2W(W)
162 = 2W^2
162/2 = W^2
81 = W^2
sqrt 81 = W
9 = W
L = 2W
L = 2(9)
L = 18
P = 2(L + W)
P = 2(18 + 9)
P = 2(27)
P = 54 <===== perimeter is 54 m
