Question

One factor for 2x2 + 16x – 18 is x + 9 ??

Answer 1

Put x = -9 in the given expression and check whether it is coming zero or not?

Answer 2

\[2x^2 + 16x -18\]

Here put x = -9 and tell whether you get zero or not?

Answer 3

Yes.

Answer 4

Then this is the factor of that expression..

See if I say that (x - 9) is the factor of expression x^2 - 81,

then firstly put x - 9 = 0

so x = 9

Put this value of x in that expression and if it comes zero then (x - 9) is the factor of that expression...

That is why I put

x + 9 = 0

x = -9
and you substitute x = -9 to get zero..