Question

I need this done :( please

Answer 1

#b

• x+4y=-26--(1)
• x-4y=8--(2)

Solve graphically

• Solution is(-9,-4.25)

#c

• x+y=2--(1)
• -3x-y=5--(2)

• Solution is(-3.5,5.5)

Both graphs attached

Answer 2

Question b

`\textsf{Equation 1:} \ \frac12x-2y=-13`

`\textsf{Equation 2:} \ x-4y=8`

Multiply Equation 2 by two:

`\implies \textsf{Equation 3:} \ x+4y=-26`

Subtract Equation 2 from Equation 3:

`\begin{aligned}x-4y & =8\\- \ \ \ x+4y & =-26\\\cline{1-2}-8y & =34\end{aligned}`

Solve for y:

`\implies -8y=34`

`\implies y = -(17)/(4)`

Substitute found value of y into Equation 2 and solve for x:

`\implies x-4\left(-(17)/(4)\right)=8`

`\implies x+17=8`

`\implies x=-9`

Question a

`\textsf{Equation 1:} \ x+y=2`

`\textsf{Equation 2:} \ -3x-y=5`

Add Equation 1 and Equation 2:

`\begin{aligned}x+y & = 2\\+ \ \ \ -3x-y & =5\\\cline{1-2}-2x & = 7\end{aligned}`

Solve for x:

`\implies -2x=7`

`\implies x = -(7)/(2)`

Substitute found value of x into Equation 1 and solve for y:

`\implies \left(-(7)/(2)\right)+y=2`

`\implies y=(11)/(2)`