Question

4х-5у=1
2х-3у=2
решите систему

Answer 1

Пошаговое объяснение:

{4х - 5у = 1

{2х - 3у = 2 | * -2

{4х - 5у = 1

{-4х + 6у = -4

{у = -3

{4х - 5у = 1

4х - 5у = 1

4х - 5 * (-3) = 1

4х + 15 = 1

4х = 1 - 15

4х = -14

х = -14 : 4

х = -3,5

(-3,5; -3)

Answer 2

$4x - 5y = 1 \: \: \: | \times 3 \\ 2x - 3y = 2 \: \: \: | \times ( - 5) \\ \\ 12x - 15y = 3 \\ - 10x + 15y = - 10 \\ \\ 12x - 10x = 3 - 10 \\2 x = - 7 \\ x = - 7 \div 2 \\ x = - 3.5 \\ \\ 2 \times ( - 3.5) - 3y = 2 \\ - 7 - 3y = 2 \\ 3y = - 7 - 2 \\ 3y = - 9 \\ y = - 9 \div 3 \\ y = - 3$

Ответ: ( - 3,5 ; - 3 )