Question

Subtract: 3I ( I - 4m + 5n ) from 4I ( 10n - 3m + 2I )

Answer 1

3l(l-4m+5n)= 3|^2-12lm+15ln.
4l(10n-3m+2l)=40ln-12lm+8l^2.
(40ln-12lm+8|^2)-(3l^2-12lm+15ln)
=40ln-15ln-12lm+12lm+8|^2-3|^2
=25ln+5|^2
=|(25n+5|)