*If you need me to do #5, DM me!
3. The area of a triangle can be given by (just plug and chug as always):

The area of the triangle is
6ft².
4. I will divide into a triangle and a rectangle (because the actual equation for the area of a pentagon requires it to be a perfect pentagon). Let's do the triangle first (height is 3 because you subtract 12 from 15):


Now we just add them:

So, the area of that pentagon is
108m².
5. You are actually wrong on this one because the area of a triangle is:

So, just halve your answer and it will be correct.
6. We can just split it into 4 triangles of equal area and then multiply the area of 1 triangle by 4 to get the total area. Let's do just that:

Multiply by 4 to get total area:

So, the area of the given rhombus is
25cm².
Answer:
summary
Step-by-step explanation:
Option a) is the right answer
Answer:
-9x + 3
Step-by-step explanation:
You would distribute first.
− ( x + 3 ) − 2 ( 4x − 3 ) → -x − 3 − 8x + 6
(If you see a negative sign in front of a parenthesis without a number, its usually a negative 1)
From there, you would combine like terms.
-x − 3 − 8x + 6 → -9x + 3