Write the decimal number as a fraction
(over 1)
0.87 = 0.87 / 1
Multiplying by 1 to eliminate 2 decimal places
we multiply top and bottom by 2 10's
Numerator (N)
N = 0.87 × 10 × 10 = 87
Denominator (D)
D = 1 × 10 × 10 = 100
N / D = 87 / 100
Simplifying our fraction
= 87/100
<span>= 87/100</span>
<span>Let x = the width
:
It says,"The length of a rectangle is 4 less than 3 times the width." write that as:
L = 3x - 4
:
If the perimeter is 40, find the dimensions of the rectangle.
:
We know: 2L + 2W = 40
:
Substitute (3x-4) for L and x for W
2(3x-4) + 2x = 40
:
6x - 8 + 2x = 40; Multiplied what's inside the brackets
:
6x + 2x = 40 + 8; do some basic algebra to find x; (added 8 to both sides)
:
8x = 48
:
x = 48/8
:
x = 6 which is the width
:
It said that L = 3x - 4, therefore:
L = 3(6) - 4
L = 18 - 4
L = 14; is the length
:
Check our solutions in the perimeter:
2(14) + 2(6) =
28 + 12 = 40</span>
(√3 - <em>i </em>) / (√3 + <em>i</em> ) × (√3 - <em>i</em> ) / (√3 - <em>i</em> ) = (√3 - <em>i</em> )² / ((√3)² - <em>i</em> ²)
… = ((√3)² - 2√3 <em>i</em> + <em>i</em> ²) / (3 - <em>i</em> ²)
… = (3 - 2√3 <em>i</em> - 1) / (3 - (-1))
… = (2 - 2√3 <em>i</em> ) / 4
… = 1/2 - √3/2 <em>i</em>
… = √((1/2)² + (-√3/2)²) exp(<em>i</em> arctan((-√3/2)/(1/2))
… = exp(<em>i</em> arctan(-√3))
… = exp(-<em>i</em> arctan(√3))
… = exp(-<em>iπ</em>/3)
By DeMoivre's theorem,
[(√3 - <em>i </em>) / (√3 + <em>i</em> )]⁶ = exp(-6<em>iπ</em>/3) = exp(-2<em>iπ</em>) = 1
Answer:
-8 and 1
Step-by-step explanation:
-8 × 1 = -8
-8 + 1 = -7
