<span>Anna learns in her science class that the human eye blinks an average of 4,200,000 times a year. What is this number expressed in scientific notation?</span>
Answer:
The number is 18
Step-by-step explanation:
You can write an equation to represent this. Let x represent the unknown number.
3x - 18 = 2x
Move 2x to the left side. Remember, "change the side, change the sign." Add 0 as a placeholder to the right of the equals sign.
3x - 2x - 18 = 0
Simplify like terms.
x - 18 = 0
Move -18 to the right of the equals sign.
x = 18
Now that we know x = 18, we can substitute it into the problem.
"Eighteen less than three times 18 is two times 18."
18 x 3 = 54
54 - 18 = 36
36 is, in fact, two times 18. We can check this by dividing 36 by 2.
36 ÷ 2 = 18
The answer is 12. Thanks (;
7.6x = 64
x = 64/7.6
x =
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8.4210526316
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So, 3.05 is NOT the solution