Question

2. Add:
(a) – 7mn + 5, 12mn + 2, 9mn – 8, – 2mn – 3

Answer 1

Answer:

12mn-4

=4(3mn-1)

Step-by-step explanation:

-7mn+5

12mn+2

9mn-8

-2mn-3

(-7+12+9-2)mn +(5+2-8-3)

= 12mn-4

= 4(3mn-1)

Answer 2

Answer:

Their sum is 12mn -4

Step-by-step explanation:

Here we have been given to add the below-given two expressions

– 7mn + 5, 12mn + 2, 9mn – 8 and  – 2mn – 3

Here as we know that we can add and subtract only the like terms or the terms having the same variables as below:

– 7mn + 5 + 12mn + 2 + 9mn – 8 + (– 2mn – 3)

= 12mn + 9mn - 7mn - 2mn + 5 + 2 - 8 - 3

= 21mn - 9mn + 7 -11

= 12mn - 4

Therefore their sum is 12mn -4