First slide
Theory of equations
Question

The sum of all real values of x satisfring the equationx25x+5x2+4x60=1 is

Difficult
Solution

Given, x25x+5x2+4x60=1
Clearly, this is possible when
I. x2+4x60=0 and x25x+50
                            or
II. x25x+5=1
                            or
III.x25x+5=1 and x2+4x60= Even integer
Case l: When x2+4x60=0
 x2+10x6x60=0
 x(x+10)6(x+10)=0  (x+10)(x6)=0  x=10 or x=6 Note that, for these two values of x,                            x25x+50
Case ll: When x25x+5=1
 x25x+4=0  x24xx+4=0  x(x4)1(x4)=0  (x4)(x1)=0  x=4 or x=1
Case III: When x25x+5=1
 x25x+6=0  x22x3x+6=0  x(x2)3(x2)=0  (x2)(x3)=0  x=2 or x=3
Now, when x=2,x2+4x60
= 4 + 8 - 60 = - 48, which is an even integer.
When x=3,x2+4x60=9+1260=39
which is not an even integer.
Thus, in this case, we get x = 2.
Hence, the sum of all real values of 
            x=10+6+4+1+2=3

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