Answer:
Step-by-step explanation:
By the triangular law of vector addition:
We have that;
From triangle ABC,
Again from triangle XYB
Since the constant has been moved to the left side, you can move on to the next step which is adding (b/2)² to both sides of the equation.
h² + 14h + (14/2)² = -31 + (14/2)²
Simplify the parenthesis and exponent.
h² + 14h + 7² = -31 + 7²
h² + 14h + 49 = -31 + 49
h² + 14h + 49 = 18
Factor the expression of the left.
(h + 7)(h + 7) = 18
Take the square root of both sides.
√(h + 7)(h + 7) = ± √9 • 2
(h + 7) = ± 3√2
h + 7 = ± 3√2
Subtract 7 from both sides.
You solutions are:
h = -7 + 3√2 → -2.7573 → -2.76
h = -7 - 3√2 → -11.2426 → -11.24
The guy ran at a speed of 8.07783 MPH
Here's how I got my answer:
1 km/hr. = 0.621371
So, if you do 
you will get your answer: 8.07783 MPH
The answer is c trust me it is c trust me the answer is c just trust me it is c
Answer:
4.58
Step-by-step explanation:
21 is not a perfect square, but lies between the perfect squares 16 and 25. Thus, √21 lies between √16 and √25, that is, between 4 and 5. Since 21 is closer to 25 than to 16, √21 is closer to 5 than to 4. A rough estimate of √21 would be 4.7.
√21 done on a calculator comes out to 4.58.
