Question

1) (2/15+1/5)•9= 2) 25/5•2,5=3) 21•(1/7)²+11•1/7=Помогите пожалуйста решить,не знаю как делать

Answer 1

N°1

1)2/15+1/5=2/15+3/15=5/15=1/3

2)1/3*9=(1*9)/3=9/3=3

Ответ:3

N°2

1)25/5*2,5=5*2 5/10=5*25/10=(5*25)/10=125/10=12 5/10=12,5

Ответ:12,5

N°3

1)(1/7)²=1/7*1/7=1/49

2)21*1/49=(21*1)/49=21/49=3/7

3)11*1/7=(11*1)/7=11/7=1 4/7

4)3/7+1 4/7=3/7+11/7=14/7=2

Ответ:2

Answer 2

Ответ:

Ответ внизу на фото

Объяснение:

Answer 3

1. (2/15 + 1/5) • 9 =

First, let's simplify the fractions inside the parentheses:

2/15 + 1/5 = (2/15) + (3/15) = 5/15

Now we can substitute back into the original expression:

(5/15) • 9 =

To simplify this, we can first divide both the numerator and denominator by 5:

5/15 = 1/3

Substituting back into the expression:

(1/3) • 9 = 3

2. 25/5 • 2.5 =

We can simplify the expression by first dividing 25 by 5:

25/5 = 5

Now we can substitute back into the expression:

5 • 2.5 = 12.5

3. 21 • (1/7)² + 11 • 1/7 =

First, let's simplify the term on the left side:

(1/7)² = (1/7) • (1/7) = 1/49

Substituting back into the expression:

21 • (1/49) + 11 • 1/7 =

To simplify this expression, we can first simplify 21/49:

21/49 = 3/7

Substituting back into the expression:

3/7 + 11/7 =

To simplify this expression, we can add the numerators and keep the denominator the same:

14/7 = 2

Therefore:

21 • (1/7)² + 11 • 1/7 = 2