Answer:
Step 4 contains his mistake . Because while changing the signs , one has to also reverse the inequality sign
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Answer:
Yes
Step-by-step explanation:
A right triangle's formula, according to Pythagorean's Theorem, is a² + b² = c². a and b are the two legs, and c is the hypotenuse. To solve, we must substitute the variables with the given measurements.
9² + 12² = 15²
Let's now solve:
81 + 144 = 225
225 = 225
The formula works out in the end, so it is a right triangle!
X - 2y = - 9
7x + 2y = 1
x - 2y = - 9
(+)
7x + 2y = 1
___________
8x = - 8
x = - 1
- 1 - 2y = - 9
2y = 8
y = 4
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The mean is 5.85; the mean standard deviation is 1.05.