Question

I need help on number 10 please

Answer 1

JL and MK have the same value, because they link heights and lengths with the same proportion: Height KL = Height JM ; Length ML = Length JK. So you can conclude that you can do:

JL = MK
-> 2x + 5 = 7x - 40
-> 5x = 45
-> x = 45/5
-> x = 9

MK = ?
-> MK = 7x - 40
-> MK = 7.(9) - 40
-> MK = 63 - 40
-> MK = 23

Answer 2

JL=MK, therefore 2x+5=7x-40
5=5x-40
45=5x
9=x

7(9)-40= 63-40=23