.further,

B - is the numerical coefficient of the linear term (i.e the number just in front of x )
For example :

For 2x^{2} + 5x + 3 = 0

2 is the number in front of x^{2} ,so 2 is the numerical coeffient of
the quadratic term or the coefficient of x^{2}

5 is the number in front of x , so 5 is the numerical coefficient of the linear term or the coefficient of x

and 3 is the constant term.

Now for x^{2} + x + 3 = 0

since x^{2} + x + 3 = 1x^{2} + 1x + 3

1 is the number in front of x^{2} , so 1 is the numerical coefficient of the quadratic term or 1 is the coefficient of x^{2}

1 is the number in front of x , so 1 is the numerical coefficient of the linear term or 1 is the coefficient of x

and 3 is the constant term.

*Note : that 2 times x = 2x *

following from that we could have

1 times x = 1x

but since 1 times 5 = 5 or a number times 1 is the number itself

we normally write 1 times x = x instead of 1x.

So if you have any variable x it is understood to be 1x

so that the coefficient of x is the number in front of x which is 1.

when you see no number in front of the variable x since x is really 1x

the number infront of x is 1 or the coefficient of x is 1.

similarly for x^{2} , 1 is the coefficient of x^{2}

for y ,1 is the coefficient of y

,
for y^{2} ,1 is the coefficient of y^{2}

etc..