Answer:
8x+9
Step-by-step explanation:
Add the like terms together.
3x+9+4x+x = 8x+9
Answer:
Step-by-step explanation:
Let's say the width is x. If the length is 3 meters more than the width, the the length is x+3.
A rectangle has 4 sides. 2 widths and 2 lengths. If the perimeter is 26 meters, you can plug in your expressions for the width and the length to solve for x.
2(x+3) +2(x)=26
2x+6+2x=26
4x+6=26
4x=20
x=5.
If x=5, that means that your with is 5 meters, and your length is 8 meters (5+3)
Answer:
1.80 2.90 3. 135
Step-by-step explanation:
1. 80°
2. 90°
3. 135°
Answer: cos(x)
Step-by-step explanation:
We have
sin ( x + y ) = sin(x)*cos(y) + cos(x)*sin(y) (1) and
cos ( x + y ) = cos(x)*cos(y) - sin(x)*sin(y) (2)
From eq. (1)
if x = y
sin ( x + x ) = sin(x)*cos(x) + cos(x)*sin(x) ⇒ sin(2x) = 2sin(x)cos(x)
From eq. 2
If x = y
cos ( x + x ) = cos(x)*cos(x) - sin(x)*sin(x) ⇒ cos²(x) - sin²(x)
cos (2x) = cos²(x) - sin²(x)
Hence:The expression:
cos(2x) cos(x) + sin(2x) sin(x) (3)
Subtition of sin(2x) and cos(2x) in eq. 3
[cos²(x)-sin²(x)]*cos(x) + [(2sen(x)cos(x)]*sin(x)
and operating
cos³(x) - sin²(x)cos(x) + 2sin²(x)cos(x) = cos³(x) + sin²(x)cos(x)
cos (x) [ cos²(x) + sin²(x) ] = cos(x)
since cos²(x) + sin²(x) = 1
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