Point slope form is
y-y1=m(x-x1)
where slope=m
and (x1,y1) is a given point
slope=(y2-y1)/(x2-x1)
slope=(6-7)/(-8-(-5))=-1/(-8+5)=-1/-3=1/3
pick any point
(x,y)
(-5,7)
y-7=1/3(x+5) or
y-6=1/3(x+8)
1 I am just typing this because it makes me put 20 characters but the answer is 1
Y=250+2x is the amount she spends
y=12x is the amount she makes
If the amount she spent = the amount she makes then she break even
250+2x=12x
250=12x-2x
250=10x
So x = 250/10=25 necklaces she needs to sell to break even
Answer is 25 necklaces