Question

1) solve by cross multuplication method 1)x+2y+1=0 2x-3y-12=0
2)3x-2y+3=0 4x+3y-42=0
3)6x-5y-16=0 7x-13y+10=0
4)2x+5y-1=0. 2x+3y-3=0

2)Solve using reducible method
15/x-y + 22/x+y =5
40/x-y + 55/x+y=13

3)The sum of digit of 2 digit number is 15.The number obtained by interchanging the digit exist the given number by 9.Find the number.

Answer 1

here is your answer by Sujeet,

Let to be 10'unit digit x
Let to be 1 unit digit y
A/q
Required Number=10x+y
Interchange Number=10y+x
then,
x+y=15

Again,
A/q
10x+y-10y+x=9
9x-9y=9
9(x-y)=9
y-x=1


solve this equation by elimination method,
y+x=15
y-x=1

________
2x=14
x=14/2
x=7

then,
y-x=1
y-7=1
y=1+7
y=8





Required Number=10x+y
=10*7+8
70+8
78


that's all...

any problem ask me......

by Sujeet