Question

1/3x-1/4y= -1; 1/5x+1/2y=4/15 find x and y​

Answer 1

Answer:

x = -2

y = 4/3 = 1.3

Step-by-step explanation:

$\frac{1}{3} x-\frac{1}{4} y=-1\\\\Taking LCM,\\\\\frac{4x-3y}{12} =-1\\\\4x-3y=-12$ )× 5------- (i)

20x - 15y = -60 ------- (iii)

$\frac{1}{5} x+\frac{1}{2} y=\frac{4}{15} \\\\Taking LCM,\\\\\frac{2x+5y}{10} =\frac{4}{15} \\\\\frac{2x+5y}{2} =\frac{4}{3} \\\\3(2x+5y)=4*2\\\\6x+15y=8$--------- (ii)

Add (ii) and (iii) ,

20x - 15y + 6x + 15y = -60 + 8

26x = -52

$x=\frac{-52}{26} \\\\x=-2$

6x + 15y = 8

6(-2) + 15y = 8

-12 + 15y = 8

15y = 20

$y=\frac{20}{15} \\\\y=\frac{4}{3} \\\\y=1.3$