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Resolving prime factor：
Enter a composite number and click the "Next" button to get the product of the composite number into several prime numbers.
Because it needs to decompose a composite number into the product of prime numbers, the composite number should be input.
Enter a composite number and click the "Next" button to get the product of the composite number into several prime numbers.
Because it needs to decompose a composite number into the product of prime numbers, the composite number should be input.
Current location：Mathematical operation > Decomposition prime factor history > Answer
Overview: 1 questions will be solved this time.Among them
☆1 equations
[ 1/1 Equation]
Work: Find the solution of equation (4+0.4n)*(20-n) = 0 .
Question type: Equation
Solution:Original question:
| ( | 4 | + | 2 5 | n | ) | ( | 20 | − | n | ) | = | 0 |
| Left side of the equation = | 4 | ( | 20 | − | n | ) | + | 2 5 | n | ( | 20 | − | n | ) |
| = | 4 | × | 20 | − | 4 | n | + | 2 5 | n | ( | 20 | − | n | ) |
| = | 80 | − | 4 | n | + | 2 5 | n | ( | 20 | − | n | ) |
| = | 80 | − | 4 | n | + | 2 5 | n | × | 20 | − | 2 5 | n | n |
| = | 80 | − | 4 | n | + | 8 | n | − | 2 5 | n | n |
| = | 80 | + | 4 | n | − | 2 5 | n | n |
| 80 | + | 4 | n | − | 2 5 | n | n | = | 0 |
After the equation is converted into a general formula, it is converted into:
( n + 10 )( n - 20 )=0
From
n + 10 = 0
n - 20 = 0
it is concluded that:：
n1=-10
n2=20
There are 2 solution(s).
解一元二次方程的详细方法请参阅：《一元二次方程的解法》