Question on How to Find Square of Specific Numbers

Topic : Square of numbers

Question : How to Find Square of numbers ending with 5?

Solution :
Let us take an example of a number say A5
a two digit number ending with 5 Square of A5 = A(A + 1)/25
means that the square always have last two digits as 25 and the other leftmost
digits will be the product of digit other than 5 and its next consecutive digit.
For example : 65 x 65 = 6 x 7 / 25 = 42 / 25 = 4225 (/ is written for partition between two operations)
Square of 125 = 12x13/25 = 15625
and you can find as many squares of the numbers ending with 5.


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Question on Equation of Parabola

Topic : Equation of parabola.

Question : y=(x-4)(x+2), find the x-intetcept and the vertex.

Answer :
This is equation of a parabola.
If you put in y=0
x-intercepts are (4,0) and (-2,0) or 4 & -2
equation can be written as
y= x^2-2x-8
for parabola of form y= ax^2+bx+c the vertex is given by ( -b/2a, (-b^2+4ac)/2a)
here a =1 , b=-2 , c= -8
so vertex is ( 2/2, (-4-32)/2)
= (1,-18) is the vertex

If you need more explanation, please leave the comments about the topic discussed above.