Answer:
X=9 or x=-9
Step-by-step explanation:
X^2=81
Can be written as
x^2-81=0
Factorize by the property:
a^2-b^2=(a-b)(a+b)
So the expression becomes:
(x-9)(x+9)=0
Therefore, either x-9=0or x+9=0
Then the solutions are x=9 or x=-9
-3z + 7 = -7 - 10z
Add 10z to both sides
7z + 7 = -7
Subtract 7 from both sides
7z = -14
Divide by 7
Z = -2
P = 24455 (1.03)x
30,000/24455 (1.03) < x
The year must be > 1.19 + 2007, or 2008.19, which means in 2009, or in 2008 + 3 months
Step-by-step explanation:
Distance = rate × time
If b is the speed of the boat in still water, and c is the speed of the current, then:
60 = (b + c) × 4
35 = (b − c) × 3.5
Simplifying:
15 = b + c
10 = b − c
Add the equations together:
25 = 2b
b = 12.5
Plug into either equation to find c:
c = 2.5
The speed of the boat is 12.5 km/h, and the speed of the current is 2.5 km/h.
Answer:
There is exactly 1 solution and it is a double root.
Step-by-step explanation:
To find this, factor the equation and solve.
x^2 + 10x - 25 = 0
(x - 5)(x - 5) = 0
Now that we have this factored, we can set each parenthesis equal to 0 and solve separately.
x - 5 = 0
x = 5
x - 5 = 0
x = 5
Because there are two of the exact same answer, we know it to be a double root.
