<span>AB=BC=CD=DE=EF = x</span>
<span>AD:DF</span>
<span>AD = AB+BC+CD = 3x, DF=DE+EF = 2x => AD:DF = 3x:2x = 3:2</span>
<span>AC:AF</span>
<span>AC = AB+BC = 2x, AF=AB+BC+CD+DE+EF = 5x => AC:AF = 2:5</span>
<span>BD:CE</span>
<span>BD = BC+CD = 2x, CE = CD+DE = 2x => BD:CE = 1:1</span>
<span>BF:BD </span>
<span>BF = BC+CD+DE+EF = 4x, BD = BC+CD = 2x => BF:BD = 4:2 = 2:1</span>
14700/21/7*49=4900
140/10/(49/7)/(10/5)=1
7>5;13>8;10>5;14>5;11>6;14>9.
3x-6y=3*(x-2y)
16a-4=4*(4a-1)
<span>6a-3=3*(2a-1)</span>