persamaan garis melalui titik (-1,-1) dab tegak lurus garis y =2x+5 adalah

y= 2x + 5
y= mx + c
[tex] m_{1} = -\frac{1}{ m_{2} } =- \frac{1}{2}[/tex]
[tex]y- y_{1} = m(x- x_{1} ) \\y+1=- \frac{1}{2}(x+1) \\ y+1=- \frac{1}{2}x- \frac{1}{2} \\ y+ \frac{1}{2}x+1+ \frac{1}{2}=0\\y+ \frac{1}{2}x+ \frac{2+1}{2} =0 \\ y+ \frac{1}{2}x+ \frac{3}{2}=0 \\ 2y+x+3=0 \\ 2y+x=-3 [/tex]

Semoga membantu