Question

хелп ми плеаз плеаз пж

Answer 1

1) ax + 8y = 20     (- 3 ; - 2)

x = - 3     y = - 2

a * (- 3) + 8 * (- 2) = 20

- 3a - 16 = 20

- 3a = 36

a = - 12

$2) \left \{ {{x-2y=-8} \atop {7x-12y=7}} \right.\\\\\left \{ {{x=2y-8} \atop {7*(2y-8)-12y=7}} \right. \\\\\left \{ {{x=2y-8} \atop {14y-56-12y=7}} \right.\\\\\left \{ {{x=2y-8} \atop {2y=63}} \right.\\\\\left \{ {{x=63-8} \atop {y=31,5}} \right.\\\\\left \{ {{x=55} \atop {y=31,5}} \right.\\\\Otvet:\boxed{(55;31,5)}$