“Solve for x…..or What is
the solution set……or What are the roots……”and the
problem has both an x2 and
an x, you make the equation equal to 0 and solve for x by
factoring.
If
the directions state:
“Solve for x……” and
there is either an x2 or an
x, you solve to get x alone.
EXAMPLE 1:
6 = 3 – x
- 3 = - 3
3 = - x
-3 = x
-
Original problem.
-
To get x alone, subtract 3 from both sides.
-
Since you CAN NOT have a negative x, you need to flip both
to their opposite signs by multiply each side by -1.
Note
the difference between the two examples (#1 above and #2
below). Example #2 is already set to equal 0 and example #1
isn't--
This
is why they are solved differently.
Changing
signs of equations:
If your answer turns out to
have a negative x, you need to “flip” the x to positive and
the number to its opposite.For
example: if your answer was
–x = 2; you need to change it to x =
-2 (by “flipping” each side to its opposite or by multiplying
or dividing both sides by –1: flipping or multiplying or
dividing will all give you the same results.)