Question

Subtract 10mn²+25 from the sum of 3mn²-4mn+21 and 4-mn+7mn².​

Answer 1

Answer:

-5mn

Step-by-step explanation:

sum of 3mn²-4mn+21 and 4-mn+7mn² is 10mn²-5mn+25

required is 10mn²-5mn+25 -(10mn²+25)

= -5mn

Answer 2

(3mn²-4mn+21) + (4-mn+7mn²)

3mn²- 4mn + 21 + 4 - mn + 7mn²

3mn² + 7mn² - 4mn - mn + 21 + 4

10mn² - 5mn + 25

Subtract 10mn²+25 from 10mn² - 5mn + 25

10mn² - 5mn + 25 - (10mn²+25)

10mn² - 5mn + 25 - 10mn² - 25

10mn² - 10mn² - 5mn + 25 - 25

0 - 5mn - 0

= - 5mn