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 :
4
Simplify —
5
Equation at the end of step 1 :
(x2) x 4
((0-————)+(31•——))+—
40 40 5
Step 2 :
x
Simplify ——
40
Equation at the end of step 2 :
(x2) x 4 ((0-————)+(31•——))+— 40 40 5Step 3 :
x2 Simplify —— 40
Equation at the end of step 3 :
x2 31x 4
((0 - ——) + ———) + —
40 40 5
Step 4 :
Adding fractions which have a common denominator :
4.1 Adding fractions which 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 + 31x 31x - x2
————————— = ————————
40 40
Equation at the end of step 4 :
(31x - x2) 4
—————————— + —
40 5
Step 5 :
Step 6 :
Pulling out like terms :
6.1 Pull out like factors :
31x - x2 = -x • (x - 31)
Calculating the Least Common Multiple :
6.2 Find the Least Common Multiple
The left denominator is : 40
The right denominator is : 5
| Prime Factor | Left Denominator | Right Denominator | L.C.M = Max {Left,Right} |
|---|---|---|---|
| 2 | 3 | 0 | 3 |
| 5 | 1 | 1 | 1 |
| Product of all Prime Factors | 40 | 5 | 40 |
Least Common Multiple:
40
Calculating Multipliers :
6.3 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 = 1
Right_M = L.C.M / R_Deno = 8
Making Equivalent Fractions :
6.4 Rewrite the two fractions into equivalent fractions
L. Mult. • L. Num. -x • (x-31) —————————————————— = ——————————— L.C.M 40 R. Mult. • R. Num. 4 • 8 —————————————————— = ————— L.C.M 40
Adding fractions that have a common denominator :
6.5 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:
-x • (x-31) + 4 • 8 -x2 + 31x + 32
——————————————————— = ——————————————
40 40
Trying to factor by splitting the middle term
6.6 Factoring -x2 + 31x + 32
The first term is, -x2 its coefficient is -1 .
The middle term is, +31x its coefficient is 31 .
The last term, "the constant", is +32
Step-1 : Multiply the coefficient of the first term by the constant -1 • 32 = -32
Step-2 : Find two factors of -32 whose sum equals the coefficient of the middle term, which is 31 .
| -32 | + | 1 | = | -31 | ||
| -16 | + | 2 | = | -14 | ||
| -8 | + | 4 | = | -4 | ||
| -4 | + | 8 | = | 4 | ||
| -2 | + | 16 | = | 14 | ||
| -1 | + | 32 | = | 31 | That's it |
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -1 and 32
-x2 - 1x + 32x + 32
Step-4 : Add up the first 2 terms, pulling out like factors :
-x • (x+1)
Add up the last 2 terms, pulling out common factors :
32 • (x+1)
Step-5 : Add up the four terms of step 4 :
(-x+32) • (x+1)
Which is the desired factorization
Final result :
(x + 1) • (32 + x)
——————————————————
40
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