For solving pair of equation, in this exercise use the method of … - Vidyadip

Question

For solving pair of equation, in this exercise use the method of elimination by equating coefficients :$13x+ 11y = 70;11x + 13y = 74$

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Answer

$13x + 11y = 70 \dots...(1)$
$11x + 13y = 74\dots ...(2)$
Adding $(1)$ and $(2)$
$13x + 11y = 70$
$+ 11x + 13y = 74$
$24x + 24y = 144$
Dividing by $24,$
$x + y = 6\dots ....(3)$
Subtracting $(2)$ from $(1)$
$13x + 11y = 70$
$- 11x + 13y = 74$
$- - - $
$2x - 2y = - 4$
Dividing by $2$
$x - y = - 2 \dots....(4)$
Adding equation $(3)$ and $(4)$
$x - y = - 2$
$+ x + y = 6$
$2x = 4$
$x = 2$
From $(3)$
$2 + y = 6$
$y = 4$

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