Daca a,b,c sunt numere naturale si a+b+c=18 ,iar 2a+b+2c=25 calculati ( a+c) ※(3a+2b+3c)

2a + b + 2c = 25

 a + b +   c = 18

din prima relatie o scad pe a doua ⇒ (2a - a) + ( b - b) + (2c - c) = 25 - 18 ⇒ a + c = 7

( a + c) x (3a+ 2b + 3c) = 7 x ( 2a + b + 2c + a + b + c) = 7 x ( 25 + 18) = 301

a + b + c = 18  

2 a + b + 2 c = 25

( a + b + c ) + ( a + c ) = 25

18 + ( a + c ) = 25

a + c = 25 - 18

a + c = 7

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( a + c ) × ( 3 a + 2 b + 3 c ) = 301

= 7 × [ ( a + b + c ) + ( 2 a + b + 2 c ) ] =

= 7 × ( 18 + 25 ) =

= 7 × 43 =

= 301