Question

solve 8x-2y=28 and x+4y=-5​

Answer 1

Step-by-step explanation:

8x-2y=28

x+4y=-5

multiple by 8 in eq 2

8x-2y=28

8x+32y=-40

subtract each other ration

-34y=68

y=-1/2

x=-3 ans

Answer 2

x = 3 and y = - 2

Step-by-step explanation:

The given equations are:

8x - 2y = 28                               ..............(1)

and x + 4y = - 5                          ..............(2)

To find, the value of x and y = ?

Multiplying equation (1) by 2, we get

2 × (8x - 2y) = 2 × 28  

16x - 4y = 56                                ..............(3)

Adding equations (2) and (3), we get

x + 4y + 16x - 4y = - 5 + 56

⇒ 17x = 51

⇒ x = $\dfrac{51}{17}$

⇒ x = 3

Put x = 3 in equation (1), we get

8(3) - 2y = 28    

⇒ 24 - 2y = 28    

⇒ - 2y = 28 - 24 = 4

⇒  y = $\dfrac{4}{-2}$ = - 2

∴ x = 3 and y = - 2