Question

Indica ordinea efectuarii operatiilor, dupa model si calculeaza a) (420 x 5 +31) - 20 x 25 b) 1950-(27 x 25 +40 :4) c) 39 x 400 + [23+2 x (23-2 x 3)] d) [(470 x 50 - 2 x 190) + 70:10 x 19]-52

Answer 1

Explicație pas cu pas:

a) (420 × 5 + 31) - 20 × 25 =

= (2 100 + 31) - 20 × 25 =

= 2 131 - 20 × 25 =

= 2 131 - 500 = 1 631

b) 1 950 - (27 × 25 + 40 : 4) =

= 1 950 - (675 + 40 : 4) =

= 1 950 - (675 + 10) =

= 1 950 - 685 = 1 265

c) 39 × 400 + [23 + 2 × (23 - 2 × 3)] =

= 39 × 400 + [23 + 2 × (23 - 6)] =

= 39 × 400 + (23 + 2 × 17) =

= 39 × 400 + (23 + 34) =

= 39 × 400 + 57 =

= 15 600 + 57 = 15 657

d) [(470 × 50 - 2 × 190) + 70 : 10 × 19] - 52 =

= [(23 500 - 2 × 190) + 70 : 10 × 19] - 52 =

= [(23 500 - 380) + 70 : 10 × 19] - 52 =

= (23 120 + 70 : 10 × 19) - 52 =

= (23 120 + 7 × 19) - 52 =

= (23 120 + 133) - 52 =

= 23 253 - 52 = 23 201