How do I do these 2 questions

Q10/
6 m/s = 21.6 km/h
6m/s =3.6 × 6 = 21.6 km/h
** 1m/s = 3.6 km /h
[tex]1 \frac{m}{s} = \frac{1}{1000} km \times \frac{60s}{1 \: min} \times \frac{60 \: min}{ 1\: h} \\ \\ = \frac{1}{1000} \times \frac{3600}{1} \\ \\ = \frac{3600}{1000} = 3. 6\: km/h[/tex]
Q14/
7x -1 =3x+7
7x - 3x = 7 +1
4x =8
x = 8/4
x =2
I hope I helped you^_^