Question

Calcular "2a - 2b" en la igualdad: (a + b; 5) = (12; a - 4)​

Answer 1

Respuesta:

$\frac{a + b}{5} = \frac{12}{a - 4} \\ (a - 4)(a + b) = 60 \\ a {}^{2} - ab - 4a - 4b = 60 \\ a {}^{2} - 4a - 4b = 60 + (a \times b ) \\ a {}^{2} = 60 + (a \times b) + 4a + 4b \\ a {}^{2} = 60 + a \times b + 4a + 4b \\ a {}^{2} = 60 + 5a \times 5b \\ a {}^{2} - 60 = 5a \times 5b$

$- 60 = 5a \times 5b - a {}^{2} \\ - 60 =5a(1 \times 5b - a)$