Answer:
Area =
square units
Step-by-step explanation:
<u>Key skills needed: Area of a parallelogram</u>
1) This shape is a parallelogram, and the way to find the area of a parallelogram is:

A = area
b = base (the side at the bottom
h = the height ( the length that runs from one side to another and makes a right angle)
2) The base (b) would be 3x. The height (h) would also be 3x
3) This means A =
3 times 3 is 9 --> and x times x is 
Therefore the area is --> 
<em>Hope you understood and have a nice day!! :D</em>
Substitution is where we first Isolate one of the unknowns, express it in terms of the other unknown, and replace the isolated unknown with the other unknown in another equation. So that each time we only need to deal with one unknown. I think you'll get a better idea here:
First name these 2 equations with 1 and 2.
4x + 5y = 7 (1)
y = 3x + 9 (2)
Since y is already isolated in (2), so we can skip the isolation step and continue to substitute.
Substitute (2) into (1).
4x + 5(3x+9) = 7
Expand.
4x + 15x + 45 = 7
Group.
19x + 45 = 7
Shift +45 to the other side and turn it into -45.
19x = 7 - 45
19x = -38
Shift x19 to the other side, turn it into /19.
X = - 38/19
X = - 2
Now we solved x already, we can just substitute x= - 2 back to equation (2).
y = 3(-2) + 9
y = - 6 + 9
y = 3
So, the answers are
x = - 2
y = 3
- 4 w - 4 = - 24
- 4w = - 20
w = 5
The weight of a plane with 81 gallons of fuel in the tank is about 44 tons
The base is the number that the exponent is attached to. So ten squared, the base is ten.