help please on 3 and 4

In (3) we're supposed to multiply both sides by 7/4 but the 7/4 got flipped over on the right hand side.
In (4) we lost a minus sign going from the second to third step. We would have been better off multiplying both sides by -6.
Hi,
For 3:
Instead of multiplying right hand side with 7/4, it was done with 4/7.
So, correct solution would be:
[tex]\left(\dfrac{7}{4}\right)\dfrac{4}{7}m=\dfrac{7}{4}22\Rightarrow m=\dfrac{7\cdot 11}{2}=\dfrac{77}2.[/tex]
For 4: on the left hand side, instead of n, correct value is --n,
then --n = 18 |·(--1) ⇒ n = --18.
Have you understood ?
Green eyes.