Algebra
QUADRATIC EQUATIONS
Step 2.
Using the division axiom, divide both sides of the equation by 4.
4x2
4
100
4
x2 = 25
Step 3.
Take the square root of both sides of the equation.
x2 = 25
x = +
_5
Thus, the roots are x = +5 and x = -5.
Step 4.
Check the roots.
3x2
= 100 - x2
3(±5)2 = 100 - (±5)2
3(25) = 100 - 25
75
= 75
If a pure quadratic equation is written in general form, a general expression can be written for
its roots. The general form of a pure quadratic is the following.
ax2 + c = 0
(2-2)
Using the subtraction axiom, subtract c from both sides of the equation.
ax2 = -c
Using the division axiom, divide both sides of the equation by a.
x2 = -
c
a
Rev. 0
Page 19
MA-02
