Fractional Exponents - Discovery Education

SD School Pre-Algebra
Program 3: Roots and Rational Numbers
QuikCheck Answer Key
True or False
3 3
1. −8 =− 8 True
2. − 16 = −16 False − 16 =−4 ; −16 is undefined.
3. An exponent that’s a simple fraction means the number in the numerator is the root of our
base number. False An exponent that’s a simple fraction means the number in the
denominator is the root of our base number.
4. If a fractional exponent is negative, take the reciprocal of the base number and then make
the exponent positive. True
5. Irrational numbers are decimals that go on forever and don’t repeat. True
6. An inequality is a mathematical expression that when both sides are multiplied by zero,
yields zero on one side and an irrational number on the other. False An inequality is a
mathematical expression that is unbalanced.
Problem Solving
3
7. 216
3
=
216 = 6
6 × 6× 6 = 216
3
8. −64 =
3
−64 =−4
−4×−4 ×−4 =−64
1
10. 81 2
=
1
81 2
= 81= 9
11. 36 −1 2
=
36 −1 2
= 1 36 = 1 6
4
2
13. 9
4
9 2
= ( 9) 4 = 3 4 = 81
0
3
14. 7
Any number to the 0 power = 1
0
7
3 3
= ( 7) 0 =1
4
9. 81 =
2
12. 8 3
=
2
3
15. −27
4
81 = 3
2
8
3 3
= ( 8) 2 = 2 2 = 4
− 27
2
3
= (
3
− 27)
2
= ( −3)
2
= 9
3× 3× 3× 3= 81