Answer:

Step-by-step explanation:
Plug in -3 for n in the equation:


Simplify. Remember to follow PEMDAS. First, solve the power:

Next, combine like terms. Note that if there are two negative signs directly next to each other, it becomes a positive sign. Add:

Your answer: 
Answer:
x=70, y=55
Step-by-step explanation:
Since the angle "y" and 2x-15 form a straight line, that means the sum of the angles, must be 180 degrees.
So using this we can derive the equation: 
The next thing you need to know is that the sum of interior angles of a triangle is 180 degrees, so if we add all the angles, we should get 180.
So using these we can derive the equation: 
So, in this case we simply have a systems of equations. We can solve this by solving for x in the second equation (sum of interior angles), and plug that into the first equation.
Original Equation:

Subtract 2y from both sides

Now let's plug this into the first equation

Plug in 180-2y as x

Distribute the 2

Combine like terms

Subtract 345 from both sides

Divide both sides by -3

So we can plug this into either equation to solve for x

Substitute in 55 as y


Subtract 110 from both sides

I think the answer is the surface area is 144cm3
Answer:
d. 2
Step-by-step explanation:
Step 1: Simplify both sides of the equation.
45a−25+7a=79
45a+−25+7a=79
(45a+7a)+(−25)=79(Combine Like Terms)
52a+−25=79
52a−25=79
Step 2: Add 25 to both sides.
52a−25+25=79+25
52a=104
Step 3: Divide both sides by 52.
52a
52
=
104
52
a=2