Answer:
The surface area of the given pyramid is 112 .
Step-by-step explanation:
Base length of the pyramid = 4 inches
Area of the base =
=
= 16
Area of its base = 16
Area of one of its triangular surface = x base x height
= x 4 x 12
= 2 x 12
= 24
Area of all its four triangular surfaces = 4 x 24
= 96
surface area of the pyramid = sum of areas of all its surfaces
= 16 + 96
= 112
The surface area of the given pyramid is 112 .
I don’t see the 2 part anywhere?
X + 2y - 6 = z..........x + 2y - z = 6
3y - 2z = 7
4 + 3x = 2y - 5z.....3x - 2y + 5z = -4
x + 2y - z = 6.....multiply by -3
3x - 2y + 5z = -4
---------------------
-3x - 6y + 3z = -18 (result of multiplying by -3)
3x - 2y + 5z = -4
--------------------add
-8y + 8z = - 22
-8y + 8z = -22
3y - 2z = 7 .....multiply by 4
----------------
-8y + 8z = -22
12y - 8z = 28 (result of multiplying by 4)
----------------add
4y = 6
y = 6/4 reduces to 3/2
-8y + 8z = -22
-8(3/2) + 8z = -22
-12 + 8z = -22
8z = -22 + 12
8z = -10
z = -10/8 reduces to -5/4
x + 2y - 6 = z
x + 2(3/2) - 6 = -5/4
x + 3 - 6 = -5/4
x - 3 = -5/4
x = -5/4 + 3
x = -5/4 + 12/4
x = 7/4
solution is (7/4, 3/2, -5/4).....x = 7/4, y = 3/2, and z = -5/4
The answer is A. The rest of the answers are not necessarily correct with the operations.