Question

efectueaza folosind factorul comun: a)398×457-398×456 b) 1456×345+1456×655 c)237×346+346×49-346×285 d)99×1457+99×457-99×1914 e)35×99+35

Answer 1

Răspuns:

a) 398

b) 1456000

c) 346

d) 0

e) 3500

Explicație pas cu pas:

a)

398 × 457 - 398 × 456 =

398 × (457 - 456) =

398 × 1 =

398

b)

1456 × 345 + 1456 × 655 =

1456 × (345 + 655) =

1456 × 1000 =

1456000

c)

237 × 346 + 346 × 49 - 346 × 285 =

346 × (237 + 49 - 285) =

346 × (286 - 285) =

346 × 1 =

346

d)

99 × 1457 + 99 × 457 - 99 × 1914 =

99 × (1457 + 457 - 1914) =

99 × (1914 - 1914) =

99 × 0 =

0

e)

35 × 99 + 35 =

35 × (99 + 1) =

35 × 100 =

3500