Answer:
Tanya is 20 years old
Step-by-step explanation:
Let the age of Vera = x years
The age of Linda is twice the age of Vera = 2x years
Tanya is four less than four times the age of Linda = 4(2x)-4 = 8x-4
Total age of Vera, Linda and Tanya is:
x+2x+8x-4
Combine the like terms:
11x-4
But now their total age is two more than nine times the age of Vera:
11x-4 = 9x+2
Solve the expression
Combine the like terms:
11x-9x=2+4
2x=6
Divide both the sides by 2
2x/2 = 6/2
x= 3
Thus the age of Vera is 3 years.
The age of Linda is 2x= 2*3 = 6 years
The age of Tanya is 8x-4 = 8*3 - 4 = 24-4 = 20years....
The bill after applying the coupon = 31.84*(85%) = 27.064
so each of them will pay : 27.064/3 = $9.021
Answer:
Step-by-step explanation:
Answer:
y=.5x-2
Step-by-step explanation:
If one line is perpendicular to another that means that their slopes are negative reciprocals
which means that the slope (or m in y=mx+b) is .5
so far we have
y=.5x+b
to solve for b we plug in (8,2)
2=.5(8)+b
2=4+b
-2=b
therefore our equation is
y=.5x-2
To solve the exponential growth application question we proceed as follows;
suppose the time, t between 1993 to 2000 is such that in 1993, t=0 and in 2000, t=7.
Note theta the population is in millions;
The exponential formula is given by:
f(t)=ae^(kt)
where;
f(t) =current value
a=initial value
k=constant of proportionality
t=time
substituting the values we have in our formula we get:
132=127e^(7k)
132/127=e^(7k)
introducing the natural logs we get:
ln (132/127)=7k
k=[ln(132/127)]/7
k=0.0055
Thus our formula will be:
f(t)=127e^(0.0055t)
The population in 2008 will be:
f(t)=127e^(15*0.0055)=127e^(0.0825)=137.922
Thus the population in 2008 is appropriately 138 million.
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