Question

Solve by Substitution

y= -3/2x -4

y= -1/2x =1

Answer 1

`\left\{\begin{array}{ccc}y=-(3)/(2)x-4\\\\y=-(1)/(2)x+1\end{array}\right\\\\-(3)/(2)x-4=-(1)/(2)x+1\ /\cdot2\\\\-3x-8=-x+2\\\\-3x+x=2+8\\\\-2x=10\ /:(-2)\\\\x=-5\\\\y=-(1)/(2)\cdot(-5)+1=2,5+1=3,5\\\\ \left\{\begin{array}{ccc}x=-5\\y=3,5\end{array}\right`

Answer 2

`\begin{cases}y= - (3)/(2)x -4 \\ y= - (1 )/(2)x +1 \end{cases}\\ \\\begin{cases}y= - (3)/(2)x -4 \\ - (3)/(2)x -4 = - (1 )/(2)x +1 \end{cases}\\ \\\begin{cases}y= - (3)/(2)x -4 \\ - (3)/(2)x +(1 )/(2)x=1+4 \end{cases}\\ \\ \begin{cases}y= - (3)/(2)x -4 \\ - (2)/(2)x=5 \end{cases}`


`\begin{cases}y= - (3)/(2)x -4 \\ - x=5/*(-1) \end{cases}\\ \\ \begin{cases}y= - (3)/(2)*(-5)-4 \\ x=-5 \end{cases}\\ \\ \begin{cases}y= (15)/(2)-4 \\ x=-5 \end{cases}\\ \\ \begin{cases}y= 7(1)/(2)-4 \\ x=-5 \end{cases}\\ \\ \begin{cases}y= 3(1 )/(2) \\ x=-5 \end{cases}\\ \\`