Use photo math. or mathpapa to help you solve the equation
point slope form of a line
y-y1 = m(x-x1)
y-4 = -3(x--5)
y-4 =-3(x+5)
to change to slope intercept form
dstribute
y-4 = -3x-15
add 4 to each side
y = -3x-15+4
y = -3x-11
Scholar #2 is correct. You take 15=-3m-18+5m-7 and combie like terms. Which will leave you with 15=2m-25. You will simplify from there, getting 20=m.