Kim is reading a book with 380 pages. She read 20 pages each day until she reached Part 2 of the book. Part 2 of the book is 160 pages long. She uses the equation 380−20d=160 to represent the number of days, d, it took her to read Part 1. How many days did it take Kim to read Part 1 of the book
To find the number of days it took Kim to read Part 1 of the book, we can solve the equation 380 - 20d = 160.
First, let's simplify the equation by subtracting 160 from both sides:
380 - 20d - 160 = 160 - 160
220 - 20d = 0
Next, let's isolate the variable by dividing both sides by 20:
(220 - 20d) / 20 = 0 / 20
220/20 - 20d/20 = 0
11 - d = 0
Now, let's solve for d by subtracting 11 from both sides:
11 - d - 11 = 0 - 11
-d = -11
Finally, we can solve for d by multiplying both sides by -1:
(-1)(-d) = (-1)(-11)
d = 11
Therefore, it took Kim 11 days to read Part 1 of the book.
380−20d=160
20d = 220
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