Answer:
the last one
Step-by-step explanation:
Answer:
10(3)^x
Step-by-step explanation:
The function contains the points (2,90) and (4,810). Use the general form y=abx to write two equations:
90=ab^2 and 810=ab^4
Solve each equation for a:
a=90/b^2 and a=810/b^4
Since a=a, set the other sides of the equations equal and solve for b.
90/b2=810/b4
Cross multiply, then divide and simplify as follows:
90b^4=810b^2
b^4/b^2=810/90
b^2=90
b^3
Now, use the value of b and the point (2,90) to find the value of a.
90=a(3^2)
a=10
So, substitute answers in original equation for a final answer of f(x)=10(3)^x.
For 1 hour:
- Jennifer can clean 1/2 of her room;
- John cal clean 1/5 of her room.
Both can clean: 1/2 + 1/5 = 5/10 + 2/10 = 7/10
1 hour -------- 7/10
x hours---------- 1
x = 1 : 7/10 = 10/7 h = 1.42857 h ( or 1 h 25 min 43 s )
Answer:
Option C.
Step-by-step explanation:
If k<0, the function g(x) = f(x) + k represents the function f(x) shifted k units downwards.
In this case, given that k=-3 (k<0). The graph was shifted 3 units down. Therefore, the correct option is Option C.
