The first one, the fourth one, and the middle one
So...notice first off, the 0.6 has 1 decimal, the 0.0024 has 4 decimals
what happens is, the dot goes poof BUT, you need to add as many zeros to each number as the other's decimals.
the 0.6 has one decimal, so 0.0024 gets an added zero and loses the dot, to become 000240.
the 0.0024 has four decimals, thus the 0.6 gets added 4 zeros then, and loses the dot, to become 060000
and then you divided that, those are the dividend and divisor.
X+7.4=49.8
-7.4 -7.4
x=49.8-7.4
x= 42.4
-5m+8
Here you go hope it helps