The annual returns will be calculated as follows:
a] Here we use the formula:
A=p(1+r/100)^n
A=future amount
p=principle
r=returns
n=time
We are given:
A=500, p=400, t=1
Plugging the values in the formula we obtain:
500=400(1+r)^1
simplifying and solving for r:
1.25=1+r
thus
r=1.25-1
r=0.25~25%
b] Using the formula above:
A=p(1+r/100)^n
A=2500+100=2600, p=2000, n=1 year
plugging the values in the equation we obtain:
2600=2000(1+r)^1
simplifying and solving for r we obtain:
2600/2000=1+r
1.3=1+r
hence
r=1.3-1
r=0.3~30%
Given:
The system of equations:


To find:
The number that can be multiplied by the second equation to eliminate the x-variable when the equations are added together.
Solution:
We have,
...(i)
...(ii)
The coefficient of x in (i) and (ii) are 1 and
respectively.
To eliminate the variable x by adding the equations, we need the coefficients of x as the additive inverse of each other, i.e, a and -a So, a+(-a)=0.
It means, we have to convert
into -1. It is possible if we multiply the equation (ii) by -5.
On multiplying equation (ii) by -5, we get
...(iii)
On adding (i) and (iii), we get

Here, x is eliminated.
Therefore, the number -5 can be multiplied by the second equation to eliminate the x-variable.
Nikkis charges are 20,40,50,80. Dave’s charges are 25 and 37.5.
Answer:
5 days
Step-by-step explanation:
Speed = 359 miles/day
Distance = 1,462 mile
Use this formula to calculate time ( in number of days);
Time = Distance / speed
Next, plug in the numbers given into the formula to calculate time;
Time = 1462 / 359 = 4.0724
Since you are told to round off in days, you will round up 4.0724 to 5 days.
Therefore, it will take Tom 5 days to drive 1,462 miles.