Question

Subtract: 3l (l − 4m + 5n) from 4l (10n − 3m + 2l)

Answer 1

First expression = 3l (l − 4m + 5n)

= 3l² − 12lm + 15ln

Second expression = 4l (10n − 3m + 2l)

= 40ln − 12lm + 8l²

Subtracting these expressions, we obtain.

   40ln − 12lm + 8l²
  15ln − 12lm + 3l²
(−)     (+)        (−)
__________________
  25ln             + 5l²

Therefore, the result is 5l² + 25ln.