Question

(4+X) (5-x) /(2+X)(7-x)=1

Answer 1

20+x-x^2=14+5x-x^2

4x=6

x=3/2

x=1.5

Answer 2

(4+X) (5-x) /(2+X)(7-x)=1/1
Now, we'll cross-multiply.
20-4x+5x-x^2*1=14-2x+7x-x^2*1
The x^2 on both sides will get cancelled. And then we will put all the constant terms on right hand side and variable terms on left hand side. Remember, first we will simplify both the sides and that the signs will change when changing the sides.
since -4x+5x=+x
   and -2x+7x=5x,
20+x=14+5x
5x-x=20-14                              (changing sides just for convenience)
6=4x
x=6/4
x=1.5

Hope it helps!
HARRY POTTER FOREVER!