Question

5x-2y=1 15x-3y=-3 линейное уравнение

Answer 1

$left { {{5x-2y=1} atop {15x-3y=-3}} right.$

 

$left { {{5x-2y=1} atop {3y=15x+3}} right.$

 

$left { {{5x-2y=1} atop {y=frac{15x+3}{3}}} right.$

 

$left { {{5x-2y=1} atop {y=frac{15x}{3}+frac{3}{3}}} right.$

 

$left { {{5x-2y=1} atop {y=5x+1}} right.$

 

$left { {{y=5x+1} atop {5x-2cdot(5x+1)=1}} right.$

 

$5x-2cdot(5x+1)=1$

 

$5x-10x-2=1$

 

$-5x-2=1$

 

$5x=-2-1$

 

$5x=-3$

 

$x=-3:5$

 

$x=-frac{3}{5}=-0,6$

 

$y=5cdot(-0,6)+1=-3+1=-2$

 

$left { {{x=-0,6} atop {y=-2}} right.$

 

Проверка:

 

$left { {{5cdot(-0,6)-2cdot(-2)=-3+4=1} atop {15cdot(-0,6)-3cdot(-2)=-9+6=-3}} right.$