Question

1 Solve the following linear equations
and x/7+y/3=5 and x/2-y/9=6​

Answer 1

Answer:

$x = 14 \: \: y = 9$

Step-by-step explanation:

$\frac{x}{7} + \frac{y}{3} = 5 \\ = \frac{3x + 7y}{21} = 5 \\ = 3x + 7y = 5 \times 21 \\ = 3x + 7y = 105 \: \: \: \: \: \: (i) \\ \frac{x}{2} - \frac{y}{9} = 6 \\ = \frac{9x - 2y}{18} = 6 \\ = 9x - 2y = 18 \times 6 \\ = 9x - 2y =108 \: \: \: \: \: \: (ii)$

$(3x + 7y = 105) \: \: \times 3\\ - (9x - 2y = 108 )\\ 9x + 21y = 315 \\ - 9x + 2y = - 108 \\ 23y = 207 \\ y = \frac{207}{23} = 9 \\ putting \: value \: of \: y \: in \: equation \: (i) \: we \: get\\ 3x + (7 \times 9) = 105 \\ 3x + 63 = 105 \\ 3x = 105 - 63 = 42 \\ x = \frac{42}{3} = 14 \\ so \: x = 14 \: \: y = 9 \: \: \: \: ans$