Question

6x+5y=-15 into intercept form

Answer 1

I think you mean like y=mx+c

6x+5y=-15 -- subtract 6x
5y=-15-6x -- divide by 5
y=(-6x/5)-3

Answer 2

$General\ equation\ for\ line\ in\ slope\ intercept\ form:\\\\y=ax+b\\\\6x+5y=-15\\ 5y=-15-6x \ \ |:5\\ y=-3-\frac{6}{5}x\\\\ In\ slope\ intercept\ form\ y=-3-\frac{6}{5}x.$