-21 = 9a - 15 - 3a -6 = 6a -1 = a
depends what 'a' =
3a = 21 Therefore, a = 21/3 a = 7
3a - 7 = -28 Therefore, 3a = -21 a = -21/3 Therefore, a = -7
a-1<2a-6<9+3a
3a x 2a =24
p=b+3a+c p-3a-c=b+3a-3a+c-c p-3a-c=b b=p-3a-c
-3(a^2 - 3a + 7)
The cube root of 27a12 is 3a4.
3.5
9a+21 3(3a+7)
a = 3