Question

5

x
−
5
y
=
−
15
3
x
−
2
y
=
−
7

Answer 1

( - 1 , 2 )

Explanation:

5x - 5y = - 15

3x - 2y = - 7

`\left \{ {{5x-5y=-15} \atop {3x-2y=-7}} \right.` ⇔
`\left \{ {{x-y=-3} \atop {3x-2y=-7}} \right.` ⇔
`\left \{ {{-3x+3y=9} \atop {3x-2y=-7}} \right.`

(1) + (2)

y = 2 -------> (1)

x = - 1

( - 1 , 2 )

Answer 2

`{\huge{\boxed{\mathbb{QUESTION}}`

`\begin{bmatrix}5x-5y=-15\\ 3x-2y=-7\end{bmatrix}`

`substitute\:x\:for\:-3+y`

`\begin{bmatrix}3\left(-3+y\right)-2y=-7\end{bmatrix}`

`{\huge{\boxed{\mathbb{SIMPLIFY}}`

`\begin{bmatrix}-9+y=-7\end{bmatrix}`

add 9 to both sides

`y=2`

Remember
`x=-3+y`

instead of
`y` we will put
`2`

`x=-3+2\\x=-1`

`{\huge{\boxed{\mathbb{ANSWER}}`

• 
  `y=2`
• 
  `x=-1`