Question

xy=6.25 , 4x+y=10 how to solve this???

Answer 1

4x+y=10
y= 10-4x
put this in equation xy= 6.25

x(10+4x) = 6.25
10x-4x^2 = 6.25

take all value at one side
as we see that it is quadratic equation so we have to take x^2 a +ve value

4x^2 - 10x +6.25 =0
as we remove decimal then
4x^2 -10x + (625/100) =0
we multiple 100 by whole equation so that demomerator 100 is cancle

400x^2 -1000x +625 =0
as is equation is divisible by 25

16x^2 -40x +25=0
factor for equation is

16x^2 -20x -20x +25 =0
4x{ 4x -5} - 5{4x - 5} =0
{4x-5} ( 4x- 5) =0

4x-5=0
x= 5/4
put this value in y = 10-4x & the value of y

y=10 - 4*5/4
y=10-5
y=5




I hope u get it !!!