Formulas

Question 1

Percent to Fraction

Ex: What is 15% in Fraction?

Answer 1

x% = x/100

Ans: 15/100 = 3/20

Question 2

Percent of a Percent

Answer 2

x * y% * z%

Question 3

Discount Percentage

Answer 3

1-(Discount Price/Original Price)

Question 4

x is y% of what no.

Answer 4

100(x/y%)

Question 5

Increasing by x%

Answer 5

(1+x%)

Question 6

Decreasing by x%

Answer 6

(1-x%)

Question 7

Sum of Consecutive Integers

Answer 7

x+(x+1)+(x+2)+(x+3)…= y

Question 8

Sum of Consecutive Even/Odd Numbers

Answer 8

x+(x+2)+(x+4)+(x+6)… = y

Question 9

Speed

Answer 9

s = d/t

Question 10

Distance

Answer 10

d = (s)(t)

Question 11

Distance given two speeds and total time

Answer 11

d = t(s1)(s2)/s1+s2

Question 12

Speed of two objects moving in the same direction

Answer 12

s1- s2 = d/t

Question 13

Speed of two objects moving towards each other

Answer 13

s1+ s2 = d/t

Question 14

Work problems formula

Answer 14

t(1/x + 1/y) = 1

Question 15

Work Problems: Find time working together

Answer 15

xy/x+y

Question 16

Solution Problems

Answer 16

ax+by=(a+b)z

Question 17

Angle of a Clock

Answer 17

θ = |30H - (11/2)M

Question 18

Find x:z given x:y & y:z

Answer 18

x/y * y/z = x/z

Question 19

Proportion Problems

Ex: If 5 boxes weigh 10 kg, how much do 4 boxes weigh?

Answer 19

x/y = w/z

Ans: 8kg

Question 20

Direct variation

Answer 20

x=ky

Question 21

Indirect variation

Answer 21

x=k/y

Question 22

Joint variation

Answer 22

x=kyz

Question 23

Combined variation

Answer 23

x=ky/z

Question 24

Arithmetic Sequence Formula

Answer 24

an = a1+(n-1)d

Question 25

Forming an Arithmetic Sequence

Answer 25

3rd term - 2nd term = 2nd term - 1st term

Question 26

Geometric Sequence

Answer 26

an = (a1)(r^n-1)

Question 27

Forming a Geometric Sequence

Answer 27

3rd term/2nd term = 2nd term/1st term

Question 28

Arithmetic Series

Answer 28

Sn = (n/2)(2a1+(n-1)d)

Question 29

Geometric Series

Answer 29

Sn = (a1(1-r^n))/1-r

Question 30

Expanding the Square of a Binomial Ex: (a+b)^2

Answer 30

a^2+2ab+b^2

Question 31

Factoring Difference of Two Squares Ex: a^2-b^2

Answer 31

(a+b)(a-b)

Question 32

Expanding Cube of a Binomial Ex: (a+b)^3

Answer 32

a^3+3a^2b+3ab^2+b^3

Question 33

Factoring Sum/Difference of Two Cubes Ex: x^3+y^3

Answer 33

(x+y)(x^2+xy+y^2)

Question 34

Reflections of a Point: Original graph: (a,b) x-axis: y-axis: y=x:

Answer 34

x-axis: (a,-b) y-axis: (-a,b) y=x: (b,a)

Question 35

Reflection of f(x) along the x-axis

Answer 35

-f(x)

Question 36

Reflection of f(x) along the y-axis

Answer 36

f(-x)

Question 37

Slope of a Perpendicular Line

Answer 37

-1/m

Question 38

Finding Slope (m) Given Two Points

Answer 38

m = (y2-y1)/(x2-x1)