Question

x+y=4;2x-5y=1 solve the simulationeous equation

Answer 1

soo given  x + y = 4 
and 2x - 5y = 1

so from x + y = 4 ⇒ x = 4 - y 

so 2x - 5y = 1 ⇒ 2(4 - y ) - 5y = 1
⇒ 8 - 7y = 1
⇒y = 1

so x = 4 - 1 = 3

so x = 3 , y = 1

Answer 2

x+y=4-----------eq(1)
2x-5y=1------------eq(2)
(1)*5  = 5x+5y=20
(2)*1  =2x-5y=1
           7x=21
=x=3

putting x value in (1)
2x-5y=1
=6-5y=1
=-5y=-5
=y=1