Răspuns:
Explicație pas cu pas:
c) 6 ( a - 2 b + c ) -3(2a - 4b + c) + 5 ( - a + 3 b - 2 c ) =
= 6 a - 12 b + 6 c - 6 a + 12 b - 3 c - 5 a + 15 b - 10 c =
= - 5 a + 15 b - 7 c
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d) 4 ( x² - 3 x - 3 ) - 2 ( 2 x² + 5 x - 7 ) + 3 ( 3 x² + 6 x - 4 ) =
= 4 x²- 12 x - 12 - 4 x² - 10 x + 14 + 9 x² + 18 x- 12 =
= ( 4 x² - 4 x² + 9 x² ) + ( -12 x - 10 x + 18 x ) + ( - 12 + 14 - 12 ) =
= 9 x² - 4 x - 10
