Question

3x-7y=-10;y-2x-3=0 by substitution

Answer 1

Answer:

$x=-1$, $y=1$

Step-by-step explanation:

$3x-7y=-10$ --- 1

$y-2x-3=0$ --- 2

$y=2x+3$ → From 2 --- 3

Substitute into 1.

$3x-7(2x+3)=-10$

$3x-14x-21=-10$

$-11x=11$

∴ $x=-1$, and hence $y=1$

Answer 2

Answer:

x = - 1

y = 1

Step-by-step explanation:

Given :

1st equation : 3x - 7y = - 10

2nd equation : y - 2x - 3 = 0

On further solving 2nd equation, we get

→ y - 2x = 3

→ y = 3 + 2x ...(i)

Putting (i) in 1st equation, we get

→ 3x - 7(3 + 2x) = - 10

→ 3x - 7(3) - 7(2x) = - 10

→ 3x - 21 - 14x = - 10

Rearranging the terms, we get

→ 3x - 14x - 21 = - 10

→ - 11x - 21 = - 10

→ - 11x = - 10 + 21

→ - 11x = 11

→ 11x = - 11

→ x = - 11/11

→ x = - 1

Putting this value in (i), we get

→ y = 3 + 2(- 1)

→ y = 3 - 2(1)

→ y = 3 - (2)

→ y = 1