Question

5. Considerando A = xy – 6x2 - 4x + 72, B = -9xy + 5xz – X + 3z e C= -10xy + 11x2 + 3x – 4z, determine:
a) A + B-C
b) A-B+C​

Answer 1

Resposta:

a) A + B-C

$xy - 6 {x}^{2} - 4x + 72 + ( - 9xy) + 5xz - x + 3z - ( - 10xy + 11 {x}^{2} + 3x - 4z) \\ xy - 6 {x}^{2} - 4x + 72 - 9xy + 5xz - x + 3z + 10xy - 11 {x}^{2} - 3x + 4z \\ 2xy - 17 {x}^{2} - 8x + 72 + 5xz + 7z \\ = - 17 {x}^{2} - 8x + 2xy + 5xz + 7z + 72$

b) A-B+C

$xy - 6 {x}^{2} - 4x + 72 - ( - 9xy + 5xz - x + 3z) - 10xy + 11 {x}^{2} + 3x - 4z \\ xy - 6 {x }^{2} - 4x + 72 + 9xy - 5xz + x - 3z - 10xy + 11 {x}^{2} + 3x - 4z \\ 5 {x}^{2} + 72 - 5xz - 7z \\ 5 {x}^{2} - 5xz - 7z + 72$