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Solve the following pair of linear equations by the substitution method. 0.2x + 0.3y = 1.3 0.4x + 0.5y = 2.3 - Mathematics

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प्रश्न

Solve the following pair of linear equations by the substitution method.

0.2x + 0.3y = 1.3

0.4x + 0.5y = 2.3

योग

उत्तर

0.2x + 0.3y = 1.3         ...(1)

0.4x + 0.5y = 2.3         ...(2)

From equation (1), we obtain

y = `(1.3 - 0.2x)/3`       ...(3)

Substituting this value in equation (2), we obtain

`0.4((1.3 - 0.2y)/0.3)+0.5y = 2.3`

⇒ `0.4x + [(0.65 - 0.1x)/0.3]= 2.31`  

⇒ 0.3 × 0.4x + 0.65 - 0.1x = 0.3 × 2.3

⇒ 0.12x + 0.65 - 0.1x = 0.69

⇒ 0.02x = 0.69 - 0.65 = 0.04

⇒ `x = 0.04/0.02`

⇒ x = 2

Substituting this value in equation x = 2 in (3), we obtain

y = `(1.3 - 0.2 xx 3)/0.3`

y = `(1.3 - 0.4)/0.3`

y = `(0.9)/(0.3)`

y = 3

∴ x = 2, y = 3

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अध्याय 3: Pair of Linear Equations in Two Variables - Exercise 3.3 [पृष्ठ ५३]

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एनसीईआरटी Mathematics [English] Class 10
अध्याय 3 Pair of Linear Equations in Two Variables
Exercise 3.3 | Q 1.4 | पृष्ठ ५३

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