Question

son ecuaciones de sustitución
7x+9y=98
4x+5y=55​

Answer 1

$7x + 9y = 98 \\ 7x = 98 - 9y \\ x = \frac{98 - 9y}{7}$

$4x + 5y = 55 \\ 4( \frac{98 - 9y}{7} ) + 5y = 55 \\ \frac{392 - 36y}{7} + 5y = 55 \\ \frac{392 - 36y + 35y}{7} = 55 \\ 392 - y = 385 \\ 392 - 385 = y \\ 7 = y$

$x = \frac{98 - 9y}{7} \\ x = \frac{98 - 9(7)}{7} \\ x = \frac{98 - 63}{7} \\ x = \frac{35}{7} \\ x = 5$

RESPUESTA :

X = 5

Y = 7