Answer:
2x - 0.4x ;
8x/5 ;
Yes
Step-by-step explanation:
Let number of miles = x
Arlene:
Double number of miles = 2 * x = 2x
Subtract 20% of the result :
2x - 20% of 2x ;
2x - 0.4x
Raul:
Divides Number of miles by 5 ; x / 5
Multiplies result by 8 ;
8 * (x/5) = 8x /5
To know if expressions are equivalent :
Let x = 10 miles
Using Arlene's expression:
2x - 0.4x
x = 10
2(10) - 0.4(10) = 16
Using Raul's expression :
8x / 5
(8*10) / 5
80/5
= 16
Since they give the same result, we can conclude that the expression are equivalent
Answer:
The answer is:
30 minutes.
Step-by-step explanation:
We are given the following information:
at 160 m/min, tool life = 5 min.
at 120 m/min, tool life = 17 min.
This means that as the speed reduced from 160 m/min to 120 m/min, the tool life increased from 5 min. to 17 min, hence the difference between the changes are:
speed = 160 - 120 = 40 m/min
tool life = 17 - 5 = 12 min.
Therefore, it can be concluded that a change of speed of 40 m/min, increases the tool life by 12 min.
40 m/min = 12 min
∴ 1 m/min = 12/40 min.
∴ 100 m/min = 12/40 × 100 = 0.3 × 100 =30 min.
The approximation to estimate will be 0.2498
2(x+2) = 60
x+2 = 30
x = 28
The correct answer is C
