The answer is d because it's the surface area
In order to find the volume of a triangular pyramid, you must use the formula (abh)/6. Therefore, I believe the answer is 12 (if [a = a] [b = h] and [c = b]).
Explanation:
Solving the first equation for
x
:
x
=
8
−
3
y
Substituting this ( for
x
)in the second equation
2
(
8
−
3
y
)
−
y
=
9
expanding
16
−
6
y
−
y
=
9
16
−
7
y
=
9
so
7
y
=
7
so
y
=
1
and
x
=
8
−
3
x
=
5