Use the Quadratic Formula to Solve to 3 s.f.
Question 1:
x
2
+
2
x
−
1
=
0
x
=
0.414
or
-2.41
Question 2:
x
2
+
12
x
−
8
=
0
x
=
0.633
or
-12.6
Question 3:
x
2
+
10
x
−
5
=
0
x
=
0.477
or
-10.5
Question 4:
3
x
2
+
8
x
−
6
=
0
x
=
0.61
or
-3.28
Question 5:
5
x
2
+
7
x
−
4
=
0
x
=
0.436
or
-1.84
Question 6:
3
x
2
−
15
x
+
8
=
0
x
=
4.39
or
0.607
