Download Using square roots to solve quadratic equations

Using square roots to solve
quadratic equations
The opposite
of squaring a
number
is taking its
square root
2x² = 8
2 2
x² = 4
√
4 =±2
x² + 12 = 5
- 12 - 12
x²
=
7
The opposite
of squaring a
√ -7
number
Can not answer
is taking its
because negative
square root
numbers do not have
square roots
there is no solution
The opposite
of squaring a
number
is taking its
square root
4x² = 9
4 4
9
x² =
√
4
9 =±3
2
4
The solutions are
1½ and -1½
3x² - 11 = 7
+ 11+ 11
3x² = 18
3 3
The opposite
x² = 6
of squaring a
=
±
2.45
√
6
number
is taking its
square root
2(x – 2)² = 18
2
2
(x
–
2)²
=
9
The opposite
of squaring a
number
is taking its
square root
√(x – 2)² = 9
x–2=±3
+2 +2
x=2±3
x=2+3
2
3
The solutions are 5 and -1
Pages 655 – 656
4 – 46 even