Use the Quadratic Formula to Solve with Surds.
Question 1:
x
2
+
4
x
−
4
=
0
x
=
-2
±
2
2
Question 2:
x
2
−
12
x
−
6
=
0
x
=
6
±
42
Question 3:
x
2
+
5
x
−
6
=
0
x
=
1
or
-6
Question 4:
x
2
−
8
x
+
1
=
0
x
=
4
±
15
Question 5:
x
2
+
11
x
−
7
=
0
x
=
-11
±
149
2
Question 6:
x
2
−
15
x
+
9
=
0
x
=
15
±
3
21
2