Math 2 Flashcards
Simplify the fraction:
4 14 5
—- x —- x —-
21 13 8
Prime numbers and cancellation (numerators with denominators) is a convenient approach.
2 x 2 x 2 x 7 x 5 5
———————– = —-
3 x 7 x 13 x 2 x 2 x 2 39
Simplify the Fraction
6x
—-
70
35
To evaluate 6.75 x 10^3:
Move the decimal to the right 3 places.
6,750.
To evaluate 72.12 x 10^-4:
Move the decimal to the left 4 places.
0.007212
To evaluate 54.197 / 10^2:
Because we are dividing by 10^2, we move the decimal to the left 2 places.
Convert 70% as a Fraction and Decimal:
Fraction:
7
—
10
Decimal
0.7
Convert 100% as Fraction and Decimal:
Fraction:
1
Decimal
1.0
Sometimes it is convenient to rewrite a fraction in order to separate a variable.
For example, three quarters of “T”.
3T
—-
4
How could be the other form of the fraction?
3
— T
4
How many zeros are there in a Billion?
9.
17 Billion = 17,000,000,000
In the question, “How many one-fourths are in 3/5 of 25/2”, where does the variable goes?
x 3 25
—- = — X —
4 5 2
x = 30
Multiplier of 7.5% increase?
1.075
Multiplier of a reduction of 8.8%?
1 - 0.088 = 0.912
In a percent difference problem, when involved decimals (those squared get smaller), I have to perform the subtraction in order of appearance of the quantities.
After, I have to divide by the basis of the comparison, which is what follows the word “than”, in the problem statements.
In a percent difference problem, when involved decimals (which squared get smaller), I have to perform the subtraction in order of appearance of the quantities.
After, I have to divide by the basis of the comparison, which is what follows the word “than”, in the problem statements.
Can I reduce terms to simplify the math when multiplying fractions?
Yes.
3/8 x 12/5 x 5/2 reduces to:
3/8 x 6/1 x 1/1
It is cross cancelation. The numerator of one fraction can get reduced by the denominator of other fraction.
Can I reduce terms to simplify the math when multiplying fractions?
Yes.
3/8 x 12/5 x 5/2 reduces to:
3/8 x 6/1 x 1/1
It is cross cancelation. The numerator of one fraction can get reduced by the denominator of other fraction.
x - 4
x + 4
-16 and -4 turns positive +4
(2x) (3x) =
6x^2
Never forget to square the variables too.
2x^2 + 11 - 6 = 0
I can factor out the 2, and divide 11/2 = 5.5
In this exercises I can also work with decimals.
“DISTANCE” FORMULA
(Rate) (Time)
Remember the fraction D/RT, and isolate the variable you need.
“RATE” FORMULA
Time
Remember the fraction D/RT, and isolate the variable you need.
“TIME” FORMULA
Rate
Remember the fraction D/RT, and isolate the variable you need.
On a Distance / Rate / Time problems, remember:
- If the *cars are moving apart and I have to find the average speed of each *car, I have to pay attention to the “Total Distance Apart from each other” number (given in the problem).
- Use the proper formula.
- Then set an equation in which I add up the Distance 1 + Distance 2 = “Total Distance Apart from each other” number (given in the problem).
Pythagorean Theorem:
If I know two sides I can get the Hypotenuse. Get it with sides 6 and 7:
(6)^2 + (7)^2 = Square Root of 85
(6)^2 = 36
+
(7)^2 = 49
——
85. -> Then, I just add the Square Root symbol.