Question

Математика помогите пожалуйста

Answer 1

Răspuns:

Explicație pas cu pas:

a) y:51,6 = 11,2:34,4 => y = 11,2·51,6:34,4 = 577,92:34,4 = 16,8

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б) 67,8/a = 7,62/6,35 => a = 67,8·6,35:7,62 = 430,53:7,62 = 56,5

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в) b: 25/6 = 4/7 : 20/21 <=> b ·6/25 = 4/7 ·21/20 =>

    b = (4/7 ·21/20):6/25 = 3/5 ·25/6 = 5/2 = 2,5

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г) 5 3/5 : 3 1/2 = 5 1/4 : x <=>

(5·5+3)/5 : (3·2+1)/2 = (5·4+1)/4 : x <=>

28/5 : 7/2 = 21/4 : x =>

x = (7/2 ·21/4):28/5 = 147/8 ·5/28 = 105/32

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д) 12,3/6 = 7x/4,2  => x = 12,3·4,2 : 42 = 1,23

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e) y : 3 1/5 = 4 1/2 : 2 1/4 => y = (3 1/5 · 4 1/2) : (2 1/4) =>

y = (3·5+1)/5 ·(4·2+1)/2 : (2·4+1)/4 = 16/5 ·9/2 : 9/4 =>

y = 8·9/5 · 4/9 = 2/5

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ж) 1/2 ·x :5 = 16 : 0,8 <=> x /10 = 20 => x = 20·10 => x = 200

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з) 0,2 : (x-2) = 1/2 : 2 1/2 <=>

2(x-2)/10 = 1/2 : 5/2 <=>

(x-2)/5 = 1/2 ·2/5 =>x-2 = 1 => x = 3

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и) 2 2/3 : 0,24 = 1 7/9 :(x+0,06) <=>

8/3 ·100/24 = 16/9 :(x+6/100) <=>

100/9 = 16/9 : (100x+6)/100 <=>

100/9 = 16/9 · 100/(100x+6) =>

1 = 16/(100x+6) =>

100x+6 = 16 => 100x = 10 => x = 1/10