Question

Solve linear systems by multiplying
3x+y=-15
2x-3y=23
​

Answer 1

x=-2, y=-9

Explanation:

Given that:

`\begin{bmatrix}3x+y=-15\\ 2x-3y=23\end{bmatrix}`

Solution:

`\mathrm{Isolate\;x\;for\;3x+y=-15:x=(-15-y)/(3)}`

`\mathrm{Substitute\:}x=(-15-y)/(3)`

`\begin{bmatrix}2\cdot (-15-y)/(3)-3y=23\end{bmatrix}`

Simplify to:

`\begin{bmatrix}(-30-11y)/(3)=23\end{bmatrix}`

`\mathrm{Isolate\;y\;for\;(-30-11y)/(3)=23:y=-9}`

`\mathrm{For\:}x=(-15-y)/(3)`

`\mathrm{Substitute\:}y=-9`

`x=(-15-\left(-9\right))/(3)`

Solve:

`x=-2`

Hence the answer is:

`x=-2,\:y=-9`

~lenvy~