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180 : ( 18 x 5 )
= 180 : 90
= 2
b) 240 : ( 2 x 3 x 4 )
= 240 : 24
= 10
c) 4400 : ( 22 x 35 )
= 4400 : 770
= \(\dfrac{40}{7}\)
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( 1/2 + 1/3 ) x 2/5
c1 = 5/6 x 2/5 = 1/3
c2 = 1/2 x 2/5 + 1/3 x 2/5
= 1/5 + 2/15
= 1/3
3/5 x 17/21 x 2/5
c1 := 17/35 x 2/5 = 34/175
c2 : = (3/5 x 2/5) x 17/21
= 6/25 x 17/21
= 34/175?
( 1/3 - 1/5 ) x 1/2
c1 : = 2/15 x 1/2
= 1/15
c2 : = 1/3 x 1/2 - 1/5 x 1/2
= 1/6 - 1/10
= 1/15
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\(=2\times x+2\times y+20=2\times\left(x+y\right)+20=2\times20+20=60\)
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\(y\times\dfrac{18}{5}-y\times\dfrac{3}{5}=2\\ y\times\left(\dfrac{18}{5}-\dfrac{3}{5}\right)=2\\ y\times3=2\\ y=2:3\\ y=\dfrac{2}{3}\)
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\(y\times\left(\dfrac{18}{5}-\dfrac{3}{5}\right)=2\\ y\times\dfrac{15}{5}=2\\ y\times3=2\\ y=2:3\\ y=\dfrac{2}{3}\)
y x 18/5 - y x 3/5=2
y x (18/5-3/5)=2
y x 3=2
y=2/3