Question

Solve sum x-y =7 , 3x -3y =15 by substitution method

Answer 1

Step-by-step explanation:

x = 7 + y .....1st

3 ( 7 + y) - 3y = 15

21 + 3y - 3y = 15

y = 0

than,

x = 7

Answer 2

Answer:

Step-by-step explanation:

$x-y=7\\3x-3y=15\\\\x=7+y\\3(7+y)-3y=15\\21+3y-3y=15\\21\neq 15$

Thus the equations are wrong