Answer:
x = -2 ± sqrt(5)
Step-by-step explanation:
x^2 + 4x – 1= 0
Add 1 to each side
x^2 + 4x – 1+1= 0+1
x^2 +4x = 1
Take the coefficient of x
4
Divide by 2
4/2 =2
Square it
2^2=4
Add it to each side
x^2 +4x+4=1+4
(x+2)^2 = 5
Take the square root of each side
sqrt((x+2)^2 )=± sqrt(5)
x+2 = ± sqrt(5)
Subtract 2 from each side
x+2-2 = -2 ± sqrt(5)
x = -2 ± sqrt(5)
Answer:
7 years
Step-by-step explanation:
Given:
Principal P = 9300
Interest rate r = 13% = 0.13
Final amount F = 17,763
Since the problem does not state that it is a compounded interest, we will assume this is a simple interest case.
The formula for simple interest is;
Interest I = Prt .....1
t = period
Final amount F = P + I
I = F-P
Substituting into equation 1;
(F-P) = Prt
t = (F-P)/Pr
Substituting the given values;
t = (17,763 - 9300)/(9300×0.13)
t = 7 years
Period = 7 years
Answer:
A) 9 and 15.
Step-by-step explanation:
First, let's see what each number's factor is:
A)
9 : 1, 3 & 9
15 : 1, 3, 5 & 15
B)
6 : 1, 2, 3 & 6
10 : 1, 2, 5 & 10
C)
8 : 1, 2, 4 & 8
12 : 1, 2, 3, 4, 6 & 12
Therefore, The number 3 is a common factor of A) 9 and 15.
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