Question

PORFAVOR ES PARA HOY: Reducir con resolucion

Answer 1

Solo recuerda que:

$(x + a)(x + b) = {x}^{2} + (a + b)x + a \times b$

...

$M = (x + 9)(x - 4) + (x + 8)(x - 5) - 2(x + 8)(x + 7) \\ M = {x}^{2} + 5x - 36 + {x}^{2} + 3x - 40 - 2( {x}^{2} + 15x + 56) \\ M = {2x}^{2} + 8x - 76 - {2x}^{2} - 30x - 112 \\ M = - 22x - 188$