Question

Solve : 3x - 5y = 4; 2y + 7 = 9x.​

Answer 1

3x - 5y = 4 ---(1)

2y + 7 = 9x ----(2)

In equation (2), x = 2/9y + 7/9

Put this value of x in equation (1)

$3( \frac{2}{9} y + \frac{7}{9} ) - 5y = 4 \\ \\ \frac{2}{3} y + \frac{7}{3} - 5y = 4 \\ \\ - \frac{13}{3} y + 7 = 12 \\ \\ - 13y + 7 = 12 \\ \\ - 13y = 12 - 7 \\ \\ - 13y = 5 \\ \\ y = - \frac{5}{13}$

Put y = -5/13 in equation (1)

3x - 5(-5/13) = 4

3x + 25/13 = 4

3x = 4 - 25/13

3x = 27/13

x = 27/13 ÷ 3

x = 9/13

So, x = 9/13 and y = -5/13

Answer 2

Answer:

Step-by-step explanation:

-20y+28