Question

А)3/5+3/7+9/7×4/15 б)(7/9-1/6):2/9×21/22

Answer 1

А) 3/5 + 3/7 + 9/7 * 4/15 = 3/5 + 3/7 + 12/35=
21/35 + 15/35 + 12/35= 48/35 = 1 целая 13/35

б) (7/9 - 1/6) : 2/9 * 21/22= 2 целые 5/8
1) 7/9 - 1/6= 14/18 - 3/18= 11/18
2) 11/18 : 2/9 = 11/18 : 9/2= 11/4
3) 11/4 * 21/22 = 21/8 = 2 целые 5/8

Answer 2

a) To solve the expression 3/5 + 3/7 + 9/7 x 4/15, we need to follow the order of operations, which is Parentheses, Exponents, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right).

There are no parentheses or exponents in the expression, so we move on to multiplication and division. 9/7 x 4/15 can be simplified by multiplying the numerators and the denominators separately:

(9 x 4) / (7 x 15) = 36/105

Now we can rewrite the expression as:

3/5 + 3/7 + 36/105

To add these fractions together, we need to find a common denominator. The smallest common multiple of 5, 7, and 105 is 105, so we can rewrite each fraction with a denominator of 105:

(3 x 21) / (5 x 21) + (3 x 15) / (7 x 15) + 36/105

= 63/105 + 45/105 + 36/105

= 144/105

= 48/35

Therefore, the value of the expression 3/5 + 3/7 + 9/7 x 4/15 is 48/35.

b) To solve the expression (7/9 - 1/6) : (2/9 x 21/22), we need to first simplify the multiplication in the denominator:

2/9 x 21/22 = (2 x 21) / (9 x 22) = 42/198

Now we can rewrite the expression as:

(7/9 - 1/6) : (42/198)

To divide fractions, we can multiply the first fraction by the reciprocal of the second fraction:

(7/9 - 1/6) x (198/42)

To simplify the fractions, we need to find a common denominator for 9 and 6, which is 18:

(7 x 2 - 1 x 3) / (9 x 2) x (198/42)

= 11/18 x (198/42)

= (11 x 11) / (2 x 3)

= 121/6

Therefore, the value of the expression (7/9 - 1/6) : (2/9 x 21/22) is 121/6.