To simplify the expression, we will first simplify the numerator and the denominator separately, then divide the simplified numerator by the simplified denominator.
The expression is:
21−207543÷131−421×152
Step 1: Convert all mixed numbers to improper fractions.
543=45×4+3=423
131=31×3+1=34
421=24×2+1=29
Step 2: Simplify the numerator.
The numerator is 423÷34−29×152.
First, perform the division:
423÷34=423×43=4×423×3=1669
Next, perform the multiplication:
29×152=2×159×2=3018
Simplify the fraction 3018 by dividing both numerator and denominator by their greatest common divisor, which is 6:
30÷618÷6=53
Now, perform the subtraction in the numerator:
1669−53
Find a common denominator for 16 and 5, which is 80.
16×569×5−5×163×16=80345−8048=80345−48=80297
So, the numerator is 80297.
Step 3: Simplify the denominator.
The denominator is 21−207.
Find a common denominator for 2 and 20, which is 20.
2×101×10−207=2010−207=2010−7=203
So, the denominator is 203.
Step 4: Divide the simplified numerator by the simplified denominator.
20380297=80297÷203
To divide by a fraction, multiply by its reciprocal:
80297×320
Simplify by canceling common factors. 20 divides into 80 four times, and 3 divides into 297 ninety-nine times.
80÷20297÷3=499
Convert the improper fraction to a mixed number:
499=2443
The simplified expression is \boxed{24\frac{3{4}}}.
What's next?