Answer:

Step-by-step explanation:
we know that
Heron's Formula is a method for calculating the area of a triangle when you know the lengths of all three sides.
so

where
a, b and c are the length sides of triangle
s is the semi-perimeter of triangle
we have

<em>Find the semi-perimeter s
</em>
s=
Find the area of triangle



simplify

7.8335 is a number between 7.833 and 8.834
Answer: 55.20$
Step-by-step explanation:
1. Add up 35% with the 15% since Mario is paying for it
2. Multiply 120(the cost without any discount/tax) with the new discount percentage
3. Now with the answer from multiplying subtract it from 120.
4. With the answer, multiply the tax percentage(0.08)
5. Now add It to the discounted price.
6. Round it to the nearest hundredth
Y - y1 = m(x - x1)
slope(m) = 13
(-2,5)...x1 = -2 and y1 = 5
sub...pay attention to ur signs
y - 5 = 13(x - (-2)...not done yet
y - 5 = 13(x + 2) <== point slope form
(5x+15)(6x-10)
= 30x^2 + 30x - 50x - 150
= 30x^2 - 20x - 150