Question

From some place at 7 a.m. 'A' started walking in the north at the speed of 5 km/hr. After 1 hr 'B' started cycling in the east at a speed of 16 km/hr. At what time they will be at a distance of 52 km apart from each other?​

Answer 1

we have,

80 {x }^{2} - 128x - 336 = 0

(dividing \: throughout \: by \: 16)

5 {x}^{2} - 8x - 21 = 0

by solving quadratic equation by factorization method.

5 {x}^{2} - 15x + 7x - 21 = 0

THEREFORE,

5x(x - 3) + 7(x - 3) = 0

(x - 3)(5x + 7) = 0

x - 3 = 0 \: or \: 5x + 7 = 0

x = 3 \: or \: x = \frac{ - 7}{5}

but \: x = \frac{ - 7}{5} \:is \: not \: acceptable

therefore \: x = 3

THUS,AFTER 3 hours from 7 a.m A & B are 20 km apart from each other.

Final \: answer \\ \: i.e \: at \: 10a.m \: they \: are 20km \: \\ apart \: from \: each \: other

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Answer:

Step-by-step explanation:

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