First Law of Indices

- If there is no visible sign before a number, the invisible sign is PLUS e.g. 8 means +8
- If two numbers have the same signs in front of them, the answer has that sign and you ADD the two numbers e.g. -1-2=-3 and 4+3=7
- If two numbers have opposite signs in front of them, the answer has the sign of the larger number and you SUBTRACT the smaller number from the larger number e.g. 4-7=-3 and 8-7= 1
- If the two numbers are equal in value but have different signs in front of them, then the result is zero e.g. -9+9= 0 and 15-15=0

Related to Sample Lesson

Each question has five choices. Click one of the choices to select your answer. You may change an answer at any time by simply clicking another choice. Click FINISH when you have completed your answers.

First Law of Indices

-3a+2a+b=

2a+b

2a-b

-a+b

5a+b

-5a+b

8t-2=

6t

-6t

82t

-10t

8t-2

7-2+8=

-2

13

-728

17

None of the given choices

-9-9-2=

99

-2

-20

20

992

6a-9b-6a+6b=

-3b

a-6b

-a-3b

12a+6b

a+3b

7+3=

3-7

37

4

10

73

-4-6-2+1=

-11

-13

13

1

4621

a-b-a+b=

2a+2b

-2a-2b

-2a+2b

0

2a-2b

-9b-1b=

-8b

10b

91b

8b

-10b

8+8-8-8=

16

8888

-16

-8

0