Question

efetue as expressoes a seguir b)3/8+2/5:2/3 c)-3/7×(-5/14+3/2) d)-1/20:(2-3/5) e)2-0,25×(-3) f)-5-3,75:0,5​

Answer 1

Olá...

b)

3/8 + 2/5 ÷ 2/3

3/8 + 2/5 × 3/2

3/8 + 1/5 × 3

3/8 + 3/5 ⇒mmc de 8, 5 = 40

15 + 24/40

39/40

c)

- 3/7 × (- 5/14 + 3/2)

- 3/7 × (- 5 + 21/14)

- 3/7 × 16/14

- 3/7 × 8/7

- 24/49

d)

- 1/20 ÷ (2 - 3/5)

- 1/20 ÷ (10 - 3/5)

- 1/20 ÷ 7/5

- 1/20 × 5/7

- 1/4 × 1/7

- 1/28

e)

2 - 0,25 × (- 3)

2 + 0,75

2,75

f)

- 5 - 3,75 ÷ 0,5

- 5 - 7,5

- 12,5

Espero ter ajudado.