Answer:
30 mph
Step-by-step explanation:
time = distance/speed
If x represents Jane's speed along the summit then her total exploration time is ...
12/x + 40/(x -5) = 2 . . . . . hours
Multiplying by (x)(x -5), we get ...
12(x -5) +40(x) = 2(x)(x -5)
Dividing by 2 and subtracting the left side gives ...
x^2 -31x +30 = 0
(x -30)(x -1) = 0 . . . . . factor
Solutions are x = 30 and x = 1, values of x that make the factors zero. A speed of 1 mph makes no sense in this problem, so ...
Jane's speed along the summit was 30 mph.
Answer:
22.5km per hour
Step-by-step explanation:
Answer:
El Dr. Potter aplicó 32 vacunas de polio y 28 de sarampión.
Step-by-step explanation:
- First, the data must be taken into account to create the equations:
- Where:
X = Number of polio vaccines and Y = Number of measles vaccines.
- 4X + 2Y = 184; (Equation 2)
Where for each polio vaccine there are 4 doses and for each measles vaccine there are 2 doses.
- We clear the variable that we want to find in each equation:
- Y = 60 - X; (And we call it equation 3)
- Y = (184-4X) / 2; (And we call it equation 4)
- Now both equations are equalized in terms of the same variable:
- Then X is cleared to find its value:
- Now we demonstrate the value of X obtained in equation 1 or 2 to give the values of Y
- Finally, both values are used to see if equation 2 gives us the correct data:
- The answer is given:
Dr. Potter gave 32 polio and 28 measles vaccines.
Y=x+3 because when x=0 y=3
Answer:
B is correct because it value become 15^9
Step-by-step explanation: