Answer:
7a-42
Step-by-step explanation:
you use the disturbtive property ( a (b-c)= ab-ac)
You already know that y equals -4. It says that x equals 3, so multiply the -4 by 3 and because it has a negative number and a positive number it will equal -12. Remember anytime you see a letter after a number it means multiply. The complete problem should be -10 because 2 is a whole number you subtract it from -12. Hope that helped you out some.
Step-by-step explanation:
the answer is regular octagon
i think
Answer:
Part 1) 
Part 2) 
Step-by-step explanation:
Part 1)
we know that
The perimeter of triangle is equal to the sum of its length sides
so

Part 2)
we know that
The area of triangle is given by the formula

we have

substitute

Answer:
-24
Step-by-step explanation:
4a+8-a
a=-2
4(-2)+8-(-2)
-8+-16
=-24
:)