Question

Solve the system of linear equations by substitution.
-x + y=-4.5
4x-y=16.5

Answer 1

`\Large \textsf{Read below}`

Explanation:

`\Large \text{$ \sf \begin{cases}\sf -x + y = -4.5\\\sf 4x - y = 16.5\end{cases}$}`

`\Large \text{$ \sf x = y + 4.5$}`

`\Large \text{$ \sf 4\:[\:y + 4.5\:] - y = 16.5$}`

`\Large \text{$ \sf 4y + 18 - y = 16.5$}`

`\Large \text{$ \sf 3y = 16.5 - 18$}`

`\Large \text{$ \sf 3y = -1.5$}`

`\Large \text{$ \sf y = -0.5$}`

`\Large \text{$ \sf x = -0.5 + 4.5$}`

`\Large \text{$ \sf x = 4$}`

`\Large \boxed{\boxed{\text{$ \sf S = \{(4,\:-0.5)\}$}}}`