Question

5x+4y=9...1 st equation
and 4x+5y=18...2nd equation then find x+y​

Answer 1

Answer:

$5x + 4y = 9 - - - - - (1) \\ 4x + 5y = 18 - - - - - (2) \\ \: \: \: \: \: using \: \: elimination \: \: method \\ multiply \: \: equation \: \: (1) \: \: by \: \: 4 \\ 4(5x + 4y) = 4(9) \\ 20x + 16y = 36 - - - - (3) \\ multiply \: \: equation \: \: (2) \: \: by \: \: 5 \\ 5(4x + 5y) = 5(18) \\ 20x + 25y = 90 - - - - - (4) \\ subtract \: \: (3) \: \: and \: \: (4) \\ 20x + 16y = 36 \\ 20x + 25y = 90 \\ - \: \: \: - \: \: \: \: - \: \: \: \: \: \: \: \: \: \: \\ - 9y = - 54 \\ y = \frac{ - 54}{ - 9} \\ y = 6 \\ put \: \: value \: \: of \: \: y \: \: in \: \: (1) \\ 5x + 4y = 9 \\ 5x + 4(6) = 9 \\ 5x + 24 = 9 \\5x = 9 - 24 \\ 5x = - 15 \\ x = \frac{ - 15}{5} \\ x = - 3 \\ so \: \: the \: \: value \: \: of \: \: x \: \: and \: \: y \: \: are \\ x = - 3 \: \: and \: \: y = 6$

I hope it will help you

Answer 2

Four human activities responsible for land degradation in India are as follows : ... Discharge of industrial effluents and wastes cause pollution and land degradation in industrial regions. (iii) In states like Gujarat, Rajasthan, Madhya Pradesh and Maharashtra overgrazing is one of the main reasons for land degradation.