Algebra
QUADRATIC EQUATIONS
Step 4.
Check the roots.
2x2
3
4x
x2
1
2
2
3
2
3
4
2
3
2
3
2
1
2
4
9
3
8
3
4
9
1
8
9
27
9
24
9
4
9
9
9
19
9
19
9
2x2
3
4x
x2
1
2(2)2
3
4(2)
(2)2
1
2(4)
3
8
4
1
8
3
5
5
5
Thus, the roots check.
Quadratic equations in which the numerical constant c is zero can always be solved by factoring.
One of the two roots is zero. For example, the quadratic equation 2x2 + 3x = 0 can be solved
by factoring. The factors are (x) and (2x + 3). Thus, the roots are x = 0 and x = - . If a
3
2
quadratic equation in which the numerical constant c is zero is written in general form, a general
expression can be written for its roots. The general form of a quadratic equation in which the
numerical constant c is zero is the following:
ax2 + bx = 0
(2-4)
The left-hand side of this equation can be factored by removing an x from each term.
x(ax + b) = 0
(2-5)
Rev. 0
Page 23
MA-02
