Addition of Algebraic Expressions Video Lecture | Mathematics for BMAT (Section 2)

okay so now let us look at how do we add
to algebraic expressions okay now this
is a quick review because we have
already covered about addition and
subtraction of algebraic expressions in
earlier lectures now let us see we are
given first algebraic expressions add 7x
squared minus 4x plus 5 and 9 X plus 10
now we have to do this in two simple
steps the first step is we write the
first expression that is 7x squared plus
4x plus 5 as is shown over here
and it is good if you can order the
variables in terms of their decreasing
powers so for example we have 7x squared
minus 4x plus 5 and no variable over
here then you write down the second
algebraic expression that is 9x plus 10
and the key idea here is to group the
like terms so if you look at 4x + 9 X
you know these are like terms why
because they have the same variable here
okay so we put down / you know we put
the 9x below for X below or 4x and you
can see that there's the constant - of
10 and 5 so we put them over here and
then there is this addition that we put
over here and then all we do is simply
do a normal addition so this 5 plus 10
is actually you do it as 5 plus of minus
10 which essentially gives you minus 5
that is what we have written over here
and then we have minus 4 plus 9 of X so
we can I'm just showing it in a
simplified manner over here so all you
do is you are just adding the
coefficients you know the constant
coefficients for X so this is minus 4
plus 9 so you are you or you can say
this is 9 minus 4 which gives you 5 and
then the X you put it as it is over here
now this one is an interesting case you
might think that oh there is no X square
over here but actually you can think of
it like as 0 multiplied
by X square which actually gives you
zero so this would turn out to be as
seven X square plus zero times X square
or it is actually seven plus zero times
X square or it is seven x square okay
and that is how we get seven x squared
plus 5x minus five now I would again
like to emphasize the key point is to
arrange your expressions properly as we
have done in the step one and the second
point is to make sure that you use the
like terms or you align the like terms
properly and take care of these signs
for example we had a minus four plus
nine over here so it is essentially nine
minus four similarly plus five minus ten
so these are the two or three things
that you need to keep in mind when we do
addition of the algebraic expressions