Step-by-step explanation:
log <base a> b = x
means
a^x = b
So
3^2 = x^2+7x+21
x^2 + 7x + 21 - 9 = 0
x^2 + 7x + 12 = 0
(x+3)(x+4)
x = -3 or -4
A is aldult tickets
b is child tickets
b = 2/3 a
7a + 12b = 90
7a + 12 x 2/3 a = 90
7a + 8a = 90
15a = 90
a = 6; b = 4
A pyramid always have a number of slant triangles equal to the number of the sides of the base.
This means that a pyramid always have the number of face which is one more than the number of sides of the base.
Therefore, given that a pyramid has n number of sides of the base, the expression for the number of faces of the pyramid is given by
number of faces = n + 1.