Question

вычислите: а) (2 3/8 + 3 7/24) : (4 2/3 - 1 1/8) ; б) (5 3/5 - 1 1/3) : (7 7/12 - 2 1/4) ​

Answer 1

Răspuns:

a = 8/5 ; б = 4/5

Explicație pas cu pas:

а) (2 3/8 + 3 7/24) : (4 2/3 - 1 1/8) = ?

2 3/8 = (2×8+3)/8 = 19/8

3 7/24 = (3×24+7)/24 = 79/24

4 2/3 = (4×3+2)/3 = 14/3

1 1/8 = (1×8+1)/8 = 9/8

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2 3/8 + 3 7/24 = ³⁾19/8 + 79/24 = (57+79)/24 = 136/24

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4 2/3 - 1 1/8 = ⁸⁾14/3 - ³⁾9/8 = (112-27)/24 = 85/24

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(2 3/8 + 3 7/24) : (4 2/3 - 1 1/8) = 136/24 : 85/24 = 136/24 × 24/85 =

= 136/85⁽¹⁷ = 8/5

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б) (5 3/5 - 1 1/3) : (7 7/12 - 2 1/4) = ?

5 3/5 = (5×5+3)/5 = 28/5

1 1/3 = (1×3+1)/3 = 4/3

7 7/12 = (7×12+7)/12 = 91/12

2 1/4 = (2×4+1)/4 = 9/4

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5 3/5 - 1 1/3 = ³⁾28/5 - ⁵⁾4/3 = (84-20)/15 = 64/15

7 7/12 - 2 1/4 = 91/12 - ³⁾9/4 = (91-27)/12 = 64/12

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(5 3/5 - 1 1/3) : (7 7/12 - 2 1/4) = 64/15 : 64/12 = 64/15 × 12/64 = 12/15⁽³ = 4/5