Answer:
friction
Step-by-step explanation:
Answer:
Hence the simplification of
is 
Step-by-step explanation:
<em>" Simplification is the process of replacing a mathematical expression by an equivalent one, that is simpler (usually shorter), </em>
<em>for example</em><em>: Simplification of a fraction to an irreducible fraction ". </em>
Here we are given a fraction as:

As both the numerator and denominator are divisible by a factor of 3 hence we take out the common factor and obtain the reduced fraction which is further irreducible.
As 66=3×22 and 81=3×27
Hence 
Hence the simplification of
is 
Answer:
(a + 3)
Step-by-step explanation:
a³ - 9a = a(a² - 9) = a(a + 3)(a - 3)
a² + a - 6 = (a - 2)(a + 3)
a⁴ + 27a = a(a³ + 27) = a(a - 3)(a² + 6a + 9) = a(a - 3)(a + 3)(a + 3)
HCF = (a + 3)
Hope it helps.
;)
<3