Answer:
21 and 22
Step-by-step explanation:
Let's work backward from that 81%: x/25 = 0.81 yields x = 20.25. Nominally, 20.25 / 25 = 0.81, but x must be an integer. Let's round 20.25 off to 20.
Thus, if Kalsom got 81%, it was a result of his having done 20 questions correctly.
81% corresponds to 20 questions correct;
82% to 20.5 questions correct, or, rounding up, to 21 questions correct;
83% to 20.75, or 21;
84% to 21 questions correct; this is the only result that makes sense (whole number of questions answered correctly)
85% to 21.25;
86% to 21.5;
87% to 21.75;
88% to 22 questions correct (this makes sense, unlike the last three)
89% to 22.25;
90% to 22.5;
91% to 22.75;
Assuming that the number of questions correct MUST be integer, then the possible number correct are 21 and 22, corresponding to 84% and 88% respectively.
Answer:
(n)*(x+y)(x-y)
Step-by-step explanation:
First of all, you take the n out, and then you use the formula of x²- y² and it will equal to (x+y)(x-y).
To find the answer, use 
, and then use the equation 
To find it's half life.
Answer:
2x² - 14x + 24
Step-by-step explanation:
Use the FOIL method (First, Outside, Inside, Last).
First, multiply the first term of both parenthesis:
2x * x = 2x²
Next, multiply the outside terms of both parenthesis:
2x * -4 = -8x
Then, multiply the inside terms of both parenthesis:
-6 * x = -6x
Finally, multiply the last terms of both parenthesis:
-6 * -4 = 24
Combine like terms:
2x² - 8x - 6x + 24
2x² (-8x - 6x) + 24
2x² (-14x) + 24
2x² - 14x + 24 is your answer.
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