Respuesta :
[tex]\bf y=\cfrac{2}{3}x\stackrel{\stackrel{b}{\downarrow }}{-3}\qquad \impliedby \begin{array}{|c|ll} \cline{1-1} slope-intercept~form\\ \cline{1-1} \\ y=\underset{y-intercept}{\stackrel{slope\qquad }{\stackrel{\downarrow }{m}x+\underset{\uparrow }{b}}} \\\\ \cline{1-1} \end{array} \\\\[-0.35em] ~\dotfill[/tex]
[tex]\bf 6x-7y=21\implies -7y=-6x+21\implies y=\cfrac{-6x+21}{-7}\implies y=\cfrac{6x-21}{7} \\\\\\ \stackrel{\textit{distributing the denominator}}{y=\cfrac{6x}{7}-\cfrac{21}{7}}\implies y=\cfrac{6}{7}x\stackrel{\stackrel{b}{\downarrow }}{-3}[/tex]
y=mx+b
b=y intercept
get into this form with no coefficient to y
Original: yint: -3
1)x+4y=12
4y=-x+12
y=-.25+3
b=3
2)2/3x+3y=-3
3y=2/3x-3
y={doesn't matter}x-1
b=-1
3)-2/3x+3y=6
3y=-2/3x+6
y={doesn't matter} +2
b=2
4) 6x-7y=21
-7y=-6x+21
y=6/7-3
b=-3
4 is the answer