=(-17) - 4
=(-17) + (-4)
=(-21)
slope = - 
calculate the slope m using the gradient formula
m= (y₂ - y₁ ) / (x₂ - x₁ )
with (x₁, y₁ ) = (0, 4) and (x₂, y₂ ) = (- 3, 6)
m =
=
= - 
Attached the solution and work.
Answer:
12.5%
Step-by-step explanation:
105 over 120 is the fraction that he got so you subtract 105 from 120 to get how much he missed. 120-105=15
He miscalculated by 15 cm out of the total of 120, 15/ 120
15/120=5/40=2.5/20 multiply the top and bottom by 5 to get the percentage out of 100. 2.5 times 5 =12.5, so he miscalculated by 12.5%
m=6
this is because m=n=6 since the triangle is an equilateral triangle
hope it helps:)))