Answer:
Step-by-step explanation:
9{[(9×9-10)-2]-5}
=9{[(81-10)-2]-5}
=9{[71-2]-5}
=9{69-5}
=9(64)
=576
Step-by-step explanation:
cot x + 2 tan x + tan³ x
Write in terms of sine and cosine:
(cos x / sin x) + 2 (sin x / cos x) + (sin³ x / cos³ x)
Find the common denominator:
(cos⁴ x / (sin x cos³ x) + 2 (sin² x cos² x / (sin x cos³ x)) + (sin⁴ x / (sin x cos³ x))
Add:
(cos⁴ x + 2 sin² x cos² x + sin⁴ x) / (sin x cos³ x)
Factor:
(sin² x + cos² x)² / (sin x cos³ x)
Pythagorean identity:
1 / (sin x cos³ x)
Multiply top and bottom by cos x:
cos x / (sin x cos⁴ x)
Simplify:
cot x sec⁴ x
Answer:
x = 3 , y = 13
Step-by-step explanation:
Note that both equations is equal to y. Set the two equations equal to each other
y = 7x - 8; y = 5x - 2
7x - 8 = y = 5x - 2
7x - 8 = 5x - 2
Isolate the x. Subtract 5x and add 8 to both sides
7x (-5x) - 8 (+8) = 5x (-5x) - 2 (+8)
7x - 5x = -2 + 8
Simplify.
(7x - 5x) = (-2 + 8)
2x = 6
Isolate the x. Divide 2 from both sides
(2x)/2 = (6)/2
x = 6/2
x = 3
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Plug in 3 for x in one of the equations.
y = 7x - 8
y = 7(3) - 8
Simplify. Remember to follow PEMDAS.
y = 7(3) - 8
y = 21 - 8
y = 13
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x = 3, y = 13 is your answer
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Corresponding sides have the same ratio, so
x/15 = 12/(12+8) = 3/5
x = 15*3/5
x = 9
