Question

4x+6/y=15 and 6x-8/y=15 solve by substitution method​

Answer 1

Answer:x=23/6

y=-18

Step-by-step explanation:

$4x+\frac{6}{y} =15 is equation 1 and 6x -\frac{8}{y}=15 is eqn 2\\ or, 4x=15-\frac{6}{y} \\or, 4x= \frac{15y-6}{y} \\or, x=\frac{15y-6}{4y} \\Now,$

substituting the value of x in eqn 2,

$or, 6 * \frac{15y-6}{4y} -\frac{8}{y} =15\\or, \frac{90y-36}{4y} -\frac{8}{y} =15\\\\or, \frac{90y-36-32y}{4y} =15\\or, 58y-36=60y\\ or,58y-60y=36\\or, -2y=36\\or, y= \frac{36}{-2} \\or,y= -18$

Again,

substituting the value of y in x,

$x=\frac{15y-6}{4y} \\x=\frac{15*-18-6}{4*-18} \\x=\frac{-276}{-72} \\x=\frac{23}{6}$