The Value of K For Which the Lines 5x+7y=3 And 15x + 21y = k Coincide Is

The value of k for which the lines 5x+7y=3 and 15x + 21y = k coincide is

(a) 9

(b) 5

(c) 7

(d) 18

(a) 9

Explanation:

5x+7y=3 --------(i)

15x + 21y = k --(ii)

Here,

`a_{1}/a_{1}"` = `b_{1}/b_{1}"` = `c_{1}/c_{1}"`

So, `frac{5}{15}` = `frac{7}{21}` = `frac{-3}{-k}`

K = 9

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CBSE Class 10 Mathematics Sample Paper-2022