Your first one ONLY. I'll answer the others when I get time.
ax + bx + ay + by
Write it this way:
(ax + bx) + (ay + by)
Factor x out of the first parentheses
x(a + b) + (ay + by)
Factor y out of the second parentheses
x(a + b) + y(a + b)
Now I will color the (a + b)'s red:
x(a + b) + y(a + b)
Note that the red parentheses (a + b) is a
factor of both those terms x(a + b) and y(a + b).
Therefore you can take out the "red" factor, you write
this
(a + b)(
When you take (a + b) out of x(a + b),
you get " x ", so put " x " next to the parenthesis
(a + b)(x
When you take (a + b) out of y(a + b), you get " y ", so put
" + y) " next to the x
(a + b)(x + y)
That's it!
Edwin
