The teacher will be very surprised to see your correct solution 😉
m /2 3*m\ 9*m 8 - - - 5*|- + ---| = --- - - 5 \5 5 / 5 5
-(1/5)*m-5*((2/5)+(3/5)*m) = (9/5)*m-(8/5)
-1/5m-5*2/5+3/5m) = (9/5)*m-(8/5)
-1/5m-5*2/5+3/5m) = 9/5m-8/5
m = 2/5 / (-5)
sum
-2/25
=
-2/25
product
-2/25
=
-2/25
-2/25