Answer:
The length of the rectangle (l) = 10 cm
The width of the rectangle (w) = 7 cm
Step-by-step explanation:
<u><em>Step(i):-</em></u>
Let 'x' be the length of the rectangle
Given that the width is 3 feet shorter than the length
The width of the rectangle = x -3
Area of the rectangle = length × width
<u><em>Step(ii):-</em></u>
Area of the rectangle = length × width
= x ( x-3)
Given that the area of the rectangle = 70 square feet
x ( x-3) = 70
⇒ x² - 3x - 70 =0
⇒ x² - 10 x + 7 x - 70 =0
⇒ x (x -10) +7( x-10) =0
⇒ ( x+7) ( x-10) = 0
⇒ x =-7 and x=10
<u><em>Final answer:</em></u>-
we choose x=10
The length of the rectangle (l) = 10 cm
The width of the rectangle (w) = 7 cm
Answer: ![\frac{\sqrt[4]{10xy^3}}{2y}](https://tex.z-dn.net/?f=%5Cfrac%7B%5Csqrt%5B4%5D%7B10xy%5E3%7D%7D%7B2y%7D)
where y is positive.
The 2y in the denominator is not inside the fourth root
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Work Shown:
![\sqrt[4]{\frac{5x}{8y}}\\\\\\\sqrt[4]{\frac{5x*2y^3}{8y*2y^3}}\ \ \text{.... multiply top and bottom by } 2y^3\\\\\\\sqrt[4]{\frac{10xy^3}{16y^4}}\\\\\\\frac{\sqrt[4]{10xy^3}}{\sqrt[4]{16y^4}} \ \ \text{ ... break up the fourth root}\\\\\\\frac{\sqrt[4]{10xy^3}}{\sqrt[4]{(2y)^4}} \ \ \text{ ... rewrite } 16y^4 \text{ as } (2y)^4\\\\\\\frac{\sqrt[4]{10xy^3}}{2y} \ \ \text{... where y is positive}\\\\\\](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B%5Cfrac%7B5x%7D%7B8y%7D%7D%5C%5C%5C%5C%5C%5C%5Csqrt%5B4%5D%7B%5Cfrac%7B5x%2A2y%5E3%7D%7B8y%2A2y%5E3%7D%7D%5C%20%5C%20%5Ctext%7B....%20multiply%20top%20and%20bottom%20by%20%7D%202y%5E3%5C%5C%5C%5C%5C%5C%5Csqrt%5B4%5D%7B%5Cfrac%7B10xy%5E3%7D%7B16y%5E4%7D%7D%5C%5C%5C%5C%5C%5C%5Cfrac%7B%5Csqrt%5B4%5D%7B10xy%5E3%7D%7D%7B%5Csqrt%5B4%5D%7B16y%5E4%7D%7D%20%5C%20%5C%20%5Ctext%7B%20...%20break%20up%20the%20fourth%20root%7D%5C%5C%5C%5C%5C%5C%5Cfrac%7B%5Csqrt%5B4%5D%7B10xy%5E3%7D%7D%7B%5Csqrt%5B4%5D%7B%282y%29%5E4%7D%7D%20%5C%20%5C%20%5Ctext%7B%20...%20rewrite%20%7D%2016y%5E4%20%5Ctext%7B%20as%20%7D%20%282y%29%5E4%5C%5C%5C%5C%5C%5C%5Cfrac%7B%5Csqrt%5B4%5D%7B10xy%5E3%7D%7D%7B2y%7D%20%5C%20%5C%20%5Ctext%7B...%20where%20y%20is%20positive%7D%5C%5C%5C%5C%5C%5C)
The idea is to get something of the form
in the denominator. In this case, 
To be able to reach the
, your teacher gave the hint to multiply top and bottom by
For more examples, search out "rationalizing the denominator".
Keep in mind that
only works if y isn't negative.
If y could be negative, then we'd have to say
. The absolute value bars ensure the result is never negative.
Furthermore, to avoid dividing by zero, we can't have y = 0. So all of this works as long as y > 0.
Answer:
the correct answer is D...
Third angle =180° - (149° + 9°)
= 22°
Thanks me if is correct!
Part (c)
We'll use this identity

to say

Similarly,

-------------------------
The key takeaways here are that

Therefore,

The identity is confirmed.
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Part (d)

Similarly,

-----------------
We'll square each equation

and

--------------------
Let's compare the results we got.

Now if we add the terms straight down, we end up with
on the left side
As for the right side, the sin(A)cos(A) terms cancel out since they add to 0.
Also note how
and similarly for the sin^2 terms as well.
The right hand side becomes
but that's always equal to 1 (pythagorean trig identity)
This confirms that
is an identity