In the base 6 number system, we would only use numerals
from 0 to 5. The idea of base 6 is just like the normal base 10 system, however
instead of using the numerals from 0 to 9, we use numerals from 0 to 5. And
instead of having a ones digit, a tens digit, a hundreds digit and so on, we
use a ones digit, a sixes digit, a thirty-sixes digit, and so on. Therefore in
base 6, the number 321 means 1 one plus
2 sixes plus 3 thirty-sixes, or 121. So to count until 15 for example, we would need:
Base 6
Base
10
1
1
2
2
3
3
4
4
5
5
10 (1 six plus 0
ones) 6
11 (1 six plus 1
one) 7
12 (1 six plus 2
ones) 8
13 9
14
10
15
11
20 (2 sixes plus 0
ones) 12
21 (2 sixes plus 1
one) 13
22
14
23
15
Expanding the given expressions using Foil:
1)(–7x + 4)(–7x + 4) =
2) (–7x + 4)(4 – 7x)=
3)(–7x + 4)(–7x – 4)=
=
4)(–7x + 4)(7x – 4)=
The third option that is (–7x + 4)(–7x – 4) is difference of two squares.
The answer is a. here’s a picture that hopefully helps explain the reasoning/work