Question

Solve 4x - 5y = 172 ; 5x - 4y = 251

Answer 1

Answer:

$4x - 5y = 172 - (i)\\ 5x - 4y = 251 - (ii) \\ \blue{\mathfrak{\underline{\large{Multiply \: {eq}^{n} \: (i) \: by \:5 \: and \: (ii) \: by \: 4}}}:} \\ 20x - 25y = 860 - (iii) \\ 20x - 16y = 1004 - (iv) \\ \blue{\mathfrak{\underline{\large{Subtract \: {eq}^{n} \: (iv) \: in \: (iii)}}}:} \\ \\ 20x - 25y = 860 \\ 20x - 16y = 1004 \\ - \: \: \: \: \: \: \: \: \: \: + \: \: \: \: \: \: \: \: \: \: \: - \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ - - - - - - - - - - - \\ - 9y = - 144 \\ \boxed{y = 16} \\ \blue{\underline{\large{put \: the \: value \:of \: y \: in \: {eq}^{n} \: (i) }}}: \\ 4x - 80 = 172 \\ 4x = 252 \\ \boxed{x = 63} \\ \\\red{\mathfrak{\underline{\large{Hope \: It \: Helps \: You }}}} \\ \green{\mathfrak{\underline{\large{Mark \: Me \: Brainliest}}}}$