Chapter 10 QuadratiC EQuations 357
Solve the equation by factoring.
1
2
xx^2 −+= 340
1
2
xx
xx
xx
2
2
2
340
2 1
2
3420
680
−+=
−+
=
−+=
()
()xx−− 42 ()= 0
xx
x
−= −=
++ ++
=
40 20
44 22
4
x= 2
Solve the equation by factoring.
−− 21 xx^282 −= 80
−−−=
−− −−=−
++=
218280
218280
218280
2
2
2
xx
xx
xx
()
1
2
21828 1
2
0
9140
7
2
2
()()
( )(
xx
xx
xx
++=
++=
+++=20)
xx
xx
+= +=
−− −−
=−
70 20
77 22
7
==− 2
If we had multiplied both sides of the original equation by −^12 , we would
have eliminated one of the steps.
PRACTICE
Solve the equation by factoring.
- −x^2 − x + 30 = 0
- –9x^2 + 25 = 0
- 0.01x^2 + 0.14x + 0.13 = 0
PRACTICE
Solve the equation by factoring.
- −−−xxxx^22
PRACTICE
Solve the equation by factoring.