3a + b = 54...when b = 9
3a + 9 = 54
3a = 54 - 9
3a = 45
a = 45/3
a = 15 <===
Hello :
<span>If f(x)= 3 ^x-1+ 4 and g(x) = 4x-7
(f-g)(x) = f(x) - g(x)= </span>3 ^x-1+ 4 - (4x - 7)
(f-g)(x) =3 ^x-1-4x +11.....( answer : a)
Answer:

Step-by-step explanation:
The surface area of a square pyramid is the sum of the area of the squared base + 4 times the area of each triangular face, therefore:

where:
is the area of the base, where
L is the length of the base
is the area of each triangular face, where
h is the height of the face
Substituting,

For the model in this problem,
L = 12
h = 8
Therefore, the surface area here is:

21*x=9*21
9*21=189
21*x=189
Divide 189 by 21 to solve for X or in this case "Blank"
189/21= 9
Answer:
7x² + 5x
Dtep-by-step explanation:
(9x² + 8x) - (2x² + 3x)
9x² + 8x - 2x²- 3x
7x² + 5x