Answer:
= 2.8
Step-by-step explanation:
If the quadrilaterals are similar, then the ratios of corresponding sides will be equal:
KL : QR = 4 : 5.6 = 4 / 5.6 = 5/7
JM : PS = 7 : 9.8 = 7 / 9.8 = 5/7
LM : RS = 3 : 4.2 = 3 / 4.2 = 5/7
This shows that the ratio of KJ : QP = 5/7
KJ : QP = 2 :
= 2 / 
Therefore, 
cross multiply: 14 = 5
Divide both sides by 5:
= 2.8
Multiply the person's weight (9 stone) by the conversion factors (14 lb / 1 stone) and (1 kg / 2.2 lb). Please show your work.
Just subtitute 5 as x in the equation given for f.
2(5)+8=18.