Form 1 maths

2006-11-14 5:45 am

2 times y is subtracted from 200. The difference is then increased by 20%. If the overall result is equal to decreasing y by 40%, find y
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回答 (3)

2006-11-14 6:06 am

✔ 最佳答案

( 200 - 2y )(120/100) = (1-40/100)y

( 200 - 2y )(1.2) = (0.6)y

240 - 2.4y = 0.6y

240 = 3y

y = 80

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2006-11-15 12:35 am

(200-2y)(1+20%)=(1-40%)y

y=80

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2006-11-14 6:07 am

(200-2y)(1+20%)=(1-40%)y
(200-2y)1.2=60%y
240-2.4y=60%y
240=3y
80=y
y=80

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