Answer:
Number 1 can form a right triangle. Numbers 2 & 3 cannot.
Step-by-step explanation:
To check if the sides are a right triangle, check if the sum of the squares of the two smaller sides equals the length of the square of the longest side. In other words, do the Pythagorean Theorem.
5² + 12² = 13²
25 + 144 = 169
169 = 169
<u><em>They are equal therefore Number 1 can form a right triangle.</em></u>
5² + 7² = 9²
25 + 49 = 81
74 = 81
<em>They are not equal, therefore Number 2 can't form a right triangle.</em>
<em />
10² + 12² = 30²
100 + 144 = 900
244 = 900
<em>They are not equal, therefore Number 3 can't form a right triangle.</em>
Suppose you add x liters of pure water to the 10 L of 25% acid solution. The new solution's volume is x + 10 L. Each L of pure water contributes no acid, while the starting solution contains 2.5 L of acid. So in the new solution, you end up with a concentration of (2.5 L)/(x + 10 L), and you want this concentration to be 10%. So we have

and so you would need to add 15 L of pure water to get the desired concentration of acid.
Answer:
$30
Step-by-step explanation:
He first has 10 dollars. Then 5 is taken off.
So, 10-5=5
His friend gives him 25 more dollars
So, 25+5= 30
Hope this helped!
Answer option D
Step-by-step explanation:

1) Since in the USA 8 x 10 ^9 messages are sent every month, that means that approximately 8 billion messages are sent.
2) We can Prime factorize it:
Note that on the right side we've picked only prime numbers. In this case, 2 and 5.
So we can rewrite 8 x 10^9 as prime factors.

3) Hence, the answer is: