Question

Calcule o valor número das expressões algébricas a seguir
A) 7x + 12, considere x = 2
B) 2abc + 3ab + 5bc,considere a = 3,b = 5 e c = -2
C)2xy² + +3x + 3xy², considere x = 3, y = 5
D)x + 4x² + 3x - 5, considere o x = 2

Answer 1

A) 7x + 12, considere x = 2

7 . ( 2 ) + 12 =

14 + 12 = 26

B) 2abc + 3ab + 5bc,considere a = 3,b = 5 e c = -2

2 . ( 3 ) . ( 5 ) . ( - 2 ) + 3 . ( 3 ) . ( 5 ) + 5 . ( 5 ) . ( - 2 ) =

6 . ( 5 ) . ( - 2 ) + 9 . ( 5 ) + 25 . ( - 2 ) =

30 . ( - 2 ) + 45 - 50 =

- 60 + 45 - 50 =

45 - 110 = - 65

C)2xy² + +3x + 3xy², considere x = 3, y = 5

2 . ( 3 ) . ( 5 )² + 3 . ( 3 ) + 3 . ( 3 ) . ( 5 )² =

6 . ( 25 ) + 9 + 9 . ( 25 ) =

150 + 9 + 225 =

159 + 225 = 384

D)x + 4x² + 3x - 5, considere o x = 2

(2) + 4.(2)² + 3.(2) - 5 =

2 + 4.(4) + 6 - 5 =

2 + 16 + 6 - 5 =

24 - 5 = 19