Solution - Adding, subtracting and finding the least common multiple
Other Ways to Solve
Adding, subtracting and finding the least common multipleStep by Step Solution
Step 1 :
9
Simplify ——
16
Equation at the end of step 1 :
3 9
((x2) - (— • x)) + ——
2 16
Step 2 :
3
Simplify —
2
Equation at the end of step 2 :
3 9 ((x2) - (— • x)) + —— 2 16Step 3 :
Rewriting the whole as an Equivalent Fraction :
3.1 Subtracting a fraction from a whole
Rewrite the whole as a fraction using 2 as the denominator :
x2 x2 • 2
x2 = —— = ——————
1 2
Equivalent fraction : The fraction thus generated looks different but has the same value as the whole
Common denominator : The equivalent fraction and the other fraction involved in the calculation share the same denominator
Adding fractions that have a common denominator :
3.2 Adding up the two equivalent fractions
Add the two equivalent fractions which now have a common denominator
Combine the numerators together, put the sum or difference over the common denominator then reduce to lowest terms if possible:
x2 • 2 - (3x) 2x2 - 3x
————————————— = ————————
2 2
Equation at the end of step 3 :
(2x2 - 3x) 9
—————————— + ——
2 16
Step 4 :
Step 5 :
Pulling out like terms :
5.1 Pull out like factors :
2x2 - 3x = x • (2x - 3)
Calculating the Least Common Multiple :
5.2 Find the Least Common Multiple
The left denominator is : 2
The right denominator is : 16
| Prime Factor | Left Denominator | Right Denominator | L.C.M = Max {Left,Right} |
|---|---|---|---|
| 2 | 1 | 4 | 4 |
| Product of all Prime Factors | 2 | 16 | 16 |
Least Common Multiple:
16
Calculating Multipliers :
5.3 Calculate multipliers for the two fractions
Denote the Least Common Multiple by L.C.M
Denote the Left Multiplier by Left_M
Denote the Right Multiplier by Right_M
Denote the Left Deniminator by L_Deno
Denote the Right Multiplier by R_Deno
Left_M = L.C.M / L_Deno = 8
Right_M = L.C.M / R_Deno = 1
Making Equivalent Fractions :
5.4 Rewrite the two fractions into equivalent fractions
Two fractions are called equivalent if they have the same numeric value.
For example : 1/2 and 2/4 are equivalent, y/(y+1)2 and (y2+y)/(y+1)3 are equivalent as well.
To calculate equivalent fraction , multiply the Numerator of each fraction, by its respective Multiplier.
L. Mult. • L. Num. x • (2x-3) • 8 —————————————————— = —————————————— L.C.M 16 R. Mult. • R. Num. 9 —————————————————— = —— L.C.M 16
Adding fractions that have a common denominator :
5.5 Adding up the two equivalent fractions
x • (2x-3) • 8 + 9 16x2 - 24x + 9
—————————————————— = ——————————————
16 16
Trying to factor by splitting the middle term
5.6 Factoring 16x2 - 24x + 9
The first term is, 16x2 its coefficient is 16 .
The middle term is, -24x its coefficient is -24 .
The last term, "the constant", is +9
Step-1 : Multiply the coefficient of the first term by the constant 16 • 9 = 144
Step-2 : Find two factors of 144 whose sum equals the coefficient of the middle term, which is -24 .
| -144 | + | -1 | = | -145 | ||
| -72 | + | -2 | = | -74 | ||
| -48 | + | -3 | = | -51 | ||
| -36 | + | -4 | = | -40 | ||
| -24 | + | -6 | = | -30 | ||
| -18 | + | -8 | = | -26 | ||
| -16 | + | -9 | = | -25 | ||
| -12 | + | -12 | = | -24 | That's it |
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -12 and -12
16x2 - 12x - 12x - 9
Step-4 : Add up the first 2 terms, pulling out like factors :
4x • (4x-3)
Add up the last 2 terms, pulling out common factors :
3 • (4x-3)
Step-5 : Add up the four terms of step 4 :
(4x-3) • (4x-3)
Which is the desired factorization
Multiplying Exponential Expressions :
5.7 Multiply (4x-3) by (4x-3)
The rule says : To multiply exponential expressions which have the same base, add up their exponents.
In our case, the common base is (4x-3) and the exponents are :
1 , as (4x-3) is the same number as (4x-3)1
and 1 , as (4x-3) is the same number as (4x-3)1
The product is therefore, (4x-3)(1+1) = (4x-3)2
Final result :
(4x - 3)2
—————————
16
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