Question

НОМЕР 1416 и 1419 помогите пожалуйста прошу срочно!!! ♥️♥️

Answer 1

Номер 1416.

1) (3; -3)

y=5x-18

-3=5*3-18

-3=-3

2) (2; 7)

y=3+2x

7=3+2*2

7=7

3) (5; -1)

y=24-5x

-1=24-5*5

-1=-1

Номер 1419

Для удобства решим системы, можно же просто подставить.

1)

$\left \{ {{0,5x-\frac{1}{3}y=1\ | *(-0.5)} \atop {0.25x+\frac{2}{3}y=3}} \right. \Longrightarrow \ \left \{ {{-0.25x+\frac{1}{6}y=-0.5 } \atop {0.25x+\frac{2}{3}y=3}} \right. \\\\\\\\+\left \{ {{-0.25x+\frac{1}{6}y=-0.5 } \atop {0.25x+\frac{2}{3}y=3}} \right.\\\\\frac{5}{6}y=2.5\\y=3\\\\0.25x+\frac{2}{3}*3=3\\0.25x+2=3\\0.25x=1\\x=4$

2)

$\left \{ {{\frac{1}{6}x+0.25y=1.5} \atop {\frac{2}{3}x+0.5y=5\ |*(-0.5) }} \right. \Longrightarrow \left \{ {{\frac{1}{6}x+0.25y=1.5} \atop {-\frac{1}{3}x-0.25y=-2.5}} \right. \\\\\\\\+\left \{ {{\frac{1}{6}x+0.25y=1.5} \atop {-\frac{1}{3}x-0.25y=-2.5}} \right. \\\\-\frac{1}{6}x=-1\\x=6\\\\\frac{1}{6}*6+0.25y=1.5\\1+0.25y=1.5\\0.25y=0.5\\y=2$

3)

$\left \{ {{0.75x-0.5y=3} \atop {0.625x-\frac{2}{3}y=1\ |*(-1.2)}} \right. \Longrightarrow \left \{ {{0.75x-0.5y=3} \atop {-0.75x+0.8y=-1.2}} \right. \\\\\\\\+\left \{ {{0.75x-0.5y=3} \atop {-0.75x+0.8y=-1.2}} \right. \\\\0.3y=1.8\\y=6\\\\0.75x-0.5*6=3\\0.75x-3=3\\0.75x=6\\x=8$

Ответ: 1 - В; 2 - D; 3 - А