а) 2 9/10 - (1 2/5 + 3/10) + 7/20First, convert all mixed numbers to improper fractions:
2 9/10 = 29/101 2/5 = 7/5
Now we can rewrite the equation:
29/10 - (7/5 + 3/10) + 7/20= 29/10 - (14/10 + 3/10) + 7/20= 29/10 - 17/10 + 7/20= 12/10 + 7/20= 6/5 + 7/20= 24/20 + 7/20= 31/20 or 1 11/20
б) 4 - (41/84 - 5/21) + 7 11/30First, find a common denominator for the fractions in the parenthesis:
41/84 = 5/125/21 = 28/84
4 - (5/12 - 28/84) + 7 11/30= 4 - (5/12 - 28/84) + 221/30= 4 - (5/12 - 28/84) + 221/30= 4 - (35/84) + 221/30= 4 - 35/84 + 221/30= 4 - 35/84 + 221/30= 120/30 - 35/84 + 221/30= 4 - 35/84 + 221/30= 120/30 - 35/84 + 221/30= 4 - 35/84 + 221/30
Now, find a common denominator and simplify the result.
а) 2 9/10 - (1 2/5 + 3/10) + 7/20
First, convert all mixed numbers to improper fractions:
2 9/10 = 29/10
1 2/5 = 7/5
Now we can rewrite the equation:
29/10 - (7/5 + 3/10) + 7/20
= 29/10 - (14/10 + 3/10) + 7/20
= 29/10 - 17/10 + 7/20
= 12/10 + 7/20
= 6/5 + 7/20
= 24/20 + 7/20
= 31/20 or 1 11/20
б) 4 - (41/84 - 5/21) + 7 11/30
First, find a common denominator for the fractions in the parenthesis:
41/84 = 5/12
5/21 = 28/84
Now we can rewrite the equation:
4 - (5/12 - 28/84) + 7 11/30
= 4 - (5/12 - 28/84) + 221/30
= 4 - (5/12 - 28/84) + 221/30
= 4 - (35/84) + 221/30
= 4 - 35/84 + 221/30
= 4 - 35/84 + 221/30
= 120/30 - 35/84 + 221/30
= 4 - 35/84 + 221/30
= 120/30 - 35/84 + 221/30
= 4 - 35/84 + 221/30
Now, find a common denominator and simplify the result.