Answer:
Step 3 is not correct (should be
, not 
Step-by-step explanation:
The expression that we have to simplify is:

We proceed step-by-step, in order to find the mistake did by Cedric:
1) First, we factorize the 5 outside:
--> this step is correct
2) We add +16 and -16 inside the brackets:
--> this step is correct
3) We rewrite the term
as the square of a bynomial, which is
, so the expression becomes
--> we notice that this step is wrong: in fact, Cedric wrote
, which is not correct.
4) Now we continue: we rewrite -16+3 as -13,

5) Finally, we multiply the 5 by the terms in the bracket:

For this case we have that, by definition of trigonometric relationships of rectangular triangles, the cosine of an angle is given by the division of the leg adjacent to the angle on the hypotenuse of the triangle. According to the figure we have:

Thus, the value of x is 9.3
Answer:

Answer:
Base=8 feet
Height=17 feet
Step-by-step explanation:
Let
Base=x
Height=3x-7
Area=68 square feet
Area of the sail boat=1/2 * base * height
68 = 1/2 * x * (3x-7)
Cross product
68 * 2 =(1) * (x) * (3x-7)
136 = 3x^2 - 7x
3x^2 - 7x - 136=0
Using quadratic formula
x= -b +or- √b^2 - 4ac / 2a
= -(-7) +or- √(-7)^2 - (4)(3)(-136) / 2(3)
= 7 +or- √49 - (-1632) / 6
= 7 +or- √49+1632) / 6
= 7 +or- √1681 / 6
=7 +or- 41 /6
x= 7+41 / 6 or 7-41 / 6
=48/6 or -34/6
=8 or -17/3
Answer:
Step-by-step explanation:
Let
Base=x
Height=3x-7
Area=68 square feet
Area of the sail boat=1/2 * base * height
68 = 1/2 * x * (3x-7)
Cross product
68 * 2 =(1) * (x) * (3x-7)
136 = 3x^2 - 7x
3x^2 - 7x - 136=0
Base of the boat can't be a negative value
Therefore,
Base = x = 8 feet
Height= 3x-7
=3(8)-7
=24-7
=17 feet
The time required for the bottle to reach the end of Nile is 963 hours
What is Speed?
Speed is defined as the rate of change of position of an object in any direction. Speed is measured as the ratio of distance to the time in which the distance was covered. Speed is a scalar quantity as it has only direction and no magnitude
Speed = Distance / Time
Given data ,
Let the speed of the bottle in the river be S = 7 km/h
Let the distance traveled by the bottle in the river be D = 6741 km
Now , the time taken by the bottle to reach the distance D with speed S is calculated by the equation
Speed = Distance / Time
and ,
Time = Distance / Speed
Substituting the values of distance and speed in the equation , we get
Time taken by the bottle = 6741 / 7
= 963 hours
Therefore , the time required is 963 hours
Hence , The time required for the bottle to reach the end of Nile is 963 hours
To learn more about speed click :
brainly.com/question/19930939
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