formulas

Question 1

(a+b)2

Answer 1

a2 + 2ab + b2

Question 2

(a-b)2

Answer 2

a2 + b2 - 2ab

Question 3

(a-b) (a+b)

Answer 3

a2 - b2

Question 4

(x+a)(x+b)

Answer 4

x2 + (a+b)2 + ab

Question 5

(a+b)2 + (a-b)2

Answer 5

2(a2 + b2)

Question 6

(a+b)2 - (a-b)2

Answer 6

4ab

Question 7

a2 + b2

Answer 7

(a+b) - 2ab

Question 8

xm xn

Answer 8

x m+n

Question 9

xm/xn

Answer 9

x m-n

Question 10

(x m)n

Answer 10

x mn

Question 11

number of diagonals in a polygon

Answer 11

n (n-3)/ 2

Question 12

exterior angle property

Answer 12

The sum of exterior angles in a polygon is always equal to 360 degrees. Therefore, for all equiangular polygons, the measure of one exterior angle is equal to 360 divided by the number of sides in the polygon.

Question 13

no. of sides of polygon

Answer 13

( n - 2 ) × 180 °

Question 14

divisibility law of 3

Answer 14

sum of digits

Question 15

divisibility law of 4

Answer 15

last 2 digits

Question 16

divisibility law of 6

Answer 16

divisible by 2 & 3

Question 17

divisibility law of 8

Answer 17

last 3 digits

Question 18

divisibility law of 9

Answer 18

sum of digits

Question 19

divisibility law of 12

Answer 19

divisible by 3 & 4

Question 20

divisibility law of 11

Answer 20

if the difference between the sum of the digits at the odd and even places equals 0 or divisible by 11, then the number is divisible by 11.

Question 21

profit =

Answer 21

SP - CP

Question 22

loss =

Answer 22

CP - SP

Question 23

SP =

Answer 23

profit + CP /

CP - loss

Question 24

profit %

Answer 24

profit * 100 / CP

Question 25

loss %

Answer 25

loss * 100 / CP

Question 26

SI =

Answer 26

PRT/100

Question 27

CI =

Answer 27

A = P (1+R/100)N 
CI = A - P

Question 28

CI (half yearly) =

Answer 28

first divide the R/2
and then multiply the n*2

then use this formula
A = P(1+R/100)N

Question 29

CI (quarter yearly) =

Answer 29

first divide the R/4
and then multiply the n*4

then use this formula
A = P(1+R/100)N

Question 30

discount % =

Answer 30

(discount/list price)*100

Question 31

percent formula =

Answer 31

(value/total value)×100

Question 32

percent increase/decreases formula =

Answer 32

(actual increase/decrease)/original amount *100

Question 33

properties of square

Answer 33

All the sides of the square are of equal measure
The sides are parallel to each other
All the interior angles of a square are at 90 degrees (i.e., right angle)
The diagonals of a square perpendicular bisect each other

Question 34

properties of rectangle

Answer 34

The opposite sides of a rectangle are of equal length
The opposite sides are parallel to each other
All the interior angles of a rectangle are at 90 degrees.
The diagonals of a rectangle bisect each other.

Question 35

properties of rhombus

Answer 35

All the four sides of a rhombus are of the same measure
The opposite sides of the rhombus are parallel to each other
The opposite angles are of the same measure
The sum of any two adjacent angles of a rhombus is equal to 180 degrees
The diagonals perpendicularly bisect each other

Question 36

properties of parallelogram

Answer 36

The opposite side of the parallelogram are of the same length
The opposite sides are parallel to each other
The diagonals of a parallelogram bisect each other
The opposite angles are of equal measure
The sum of two adjacent angles of a parallelogram is equal to 180 degrees

Question 37

properties of trapezium

Answer 37

Only one pair of the opposite side of a trapezium is parallel to each other
The two adjacent sides of a trapezium are supplementary (180 degrees)
The diagonals of a trapezium bisect each other in the same ratio

Question 38

properties of kite

Answer 38

The pair of adjacent sides of a kite are of the same length
The largest diagonal of a kite bisect the smallest diagonal
Only one pair of opposite angles are of the same measure.