Question

Daca a+b+c sunt numere naturale astfel incat a+b=100 si b+c=150, calculeaza:a+2b+c= ; 2a+4b+2c; 5a+10b+5c; c-a=;

Answer 1

Răspuns

Explicație pas cu pas:

a + b = 100   si  b + c = 150

____________________

a + 2 b + c = 250

= ( a + b ) + ( b + c ) =

= 100 + 150 =

= 250

______________________

2 a + 4 b + 2 c = 500

= 2 a + 2 b + 2 b + 2 c =

= 2 × ( a + b ) + 2 × ( b + c ) =

= 2 × 100 + 2 × 150 =

= 200 + 300 =

= 500

_________________

5 a + 10 b + 5 c = 1 250

5 a + 5 b + 5 b + 5 c =

= 5 × ( a + b ) + 5 × ( b + c ) =

= 5 × 100 + 5 × 150 =

= 500 + 750 =

= 1 250

___________

c - a = 50

( b + c ) - ( a + b ) = 150 - 100

b + c - a - b = 50

c - a = 50