Question

what must be added to the sum of x square - 4 x + 7 and 2 X square + 5 x minus 9 to get 0​

Answer 1

Answer:

-3x² -x -16

Step-by-step explanation:

( x² -4x +7 ) + ( 2x² +5x -9 )  + y  = 0

(  3x² +x + 16 ) + y    = 0

                        y  =  -3x² -x  -16

∴  -3x² -x -16  is to be added to get  zero

Answer 2

Answer:

equation,

(x²-4x+7) + (2x²+5x-9)

x²+2x-4x+5x+7-9

=3x²+x-2

Let added number be N

3x²+x-2 + n = 0

n= -(3x²+x-2)

n= -3x²-x+2

[Sign Changed because of rules]

Hence The Answer Is

-3x²-x+2, should be added

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