Base is 12 feet square so 12 *12 = 144 square feet
each triangle has base of 12 feet and height of 8 feet
area of triangle = 1/2 x base x height = 1/2 x 12 x 8 = 48 square feet
48 x 4 triangles = 192 square feet
total: 192 + 144 = 336 square feet
Answer:
the first one
the third one
the fourth one
Step-by-step explanation:
1. x <em>does</em> equal 9
2. the equation would lead to x being canceled out so there would be an x in your answer
3. x <em>does</em> equal 30
4. x <em>does</em> equal 6
5. x should equal 135
I'd suggest using "elimination by addition and subtraction" here, altho' there are other approaches (such as matrices, substitution, etc.).
Note that if you add the 3rd equation to the second, the x terms cancel out, and you are left with the system
- y + 3z = -2
y + z = -2
-----------------
4z = -4, so z = -1.
Next, multiply the 3rd equation by 2: You'll get -2x + 2y + 2z = -2.
Add this result to the first equation. The 2x terms will cancel, leaving you with the system
2y + 2z = -2
y + z = 4
This would be a good time to subst. -1 for z. We then get:
-2y - 2 = -2. Then y must be 0. y = 0.
Now subst. -1 for z and 0 for y in any of the original equations.
For example, x - (-1) + 3(0) = -2, so x + 1 = -2, or x = -3.
Then a tentative solution is (-3, -1, 0).
It's very important that you ensure that this satisfies all 3 of the originale quations.
Answer:
20
Step-by-step explanation:
