Question

A) 1/3-2/5 b) 1/5+2/7 c) 3/45-1/27 60 баллов

Answer 1

а) 1/3 - 2/5=5/15 - 6/15=-1/15

в) 1/5 + 2/7=7/35 + 10/35=17/35

с) 3/45 - 1/27=3/(5*9) - 1/(3*9)=

   9/(45*3) - 5/(27*5)=4/135.

Answer 2

To solve the given expressions, let's simplify each one step by step:

A) 1/3 - 2/5:

To subtract fractions, we need a common denominator. In this case, the common denominator is 15.

1/3 = (1/3) * (5/5) = 5/15 2/5 = (2/5) * (3/3) = 6/15

Now we can subtract:

5/15 - 6/15 = (5 - 6)/15 = -1/15

Therefore, the result of 1/3 - 2/5 is -1/15.

B) 1/5 + 2/7:

To add fractions, we need a common denominator. In this case, the common denominator is 35.

1/5 = (1/5) * (7/7) = 7/35 2/7 = (2/7) * (5/5) = 10/35

Now we can add:

7/35 + 10/35 = (7 + 10)/35 = 17/35

Therefore, the result of 1/5 + 2/7 is 17/35.

C) 3/45 - 1/27:

To subtract fractions, we need a common denominator. In this case, the common denominator is 135.

3/45 = (3/45) * (3/3) = 9/135 1/27 = (1/27) * (5/5) = 5/135

Now we can subtract:

9/135 - 5/135 = (9 - 5)/135 = 4/135

Therefore, the result of 3/45 - 1/27 is 4/135.

In summary: A) 1/3 - 2/5 = -1/15 B) 1/5 + 2/7 = 17/35 C) 3/45 - 1/27 = 4/135

I'm not sure what you mean by "60 баллов." If you have any further questions, feel free to ask!