Question

a) 18 x (33 x 26) = (26 x 18) x ▼
b) 345 x ▼ = 345
c) 17 x (25 + 44) = 17 x 25 + 17 x ▼
d) 23 x (112 – 14) = 23 x 112 - ▼ x 14

Answer 1

A) 18 × (33×26) = (26×18) × ♦

18 × 858 = 468 × ♦

15.444 = 468 × ♦

15.444÷468 = ♦

♦ = 15.444÷468

♦ = 33

B) 345 × ♦ = 345

♦ = 345÷345

♦ = 1

C) 17 × (25+44) = 17 × 25 + 17 × ♦

17 × 69 = 425 + 17 × ♦

1.173 = 425 + 17 × ♦

♦= 44, pois:

17×44= 748 + 425 ➡ 1.173

D) 23 × (112-14) = 23 × 112 - ♦ × 14

23 × 98 = 2.576 - ♦ × 14

2.254 = 2.576 - ♦ × 14

♦= -23, pois:

-23×14= -322

2254= 2.576 - 322

2254= 2254