Answer:
Her speed on the summit was 35 mph.
Step-by-step explanation:
Her speed on the summit was "x" mph while her speed while climbing was "x - 10" mph. The distance she rode uphill was 55 miles and on the summit it was 28 miles. The total time she explored the mountain was 3 hours. Therefore:
time uphill = distance uphill / speed uphill = 55 / (x - 10)
time summit = distance summit / speed summit = 28 / x
total time = time uphill + time summit
3 = [55 / (x - 10)] + 28 / x
3 = [55*x + 28*(x - 10)]/[x*(x - 10)]
3*x*(x - 10) = 55*x + 28*x - 280
3x² - 30*x = 83*x - 280
3x² - 113*x + 280 = 0
x1 = {-(-113) + sqrt[(-113)² - 4*(3)*(280)]}/(2*3) = 35 mph
x2 = {-(-113) - sqrt[(-113)² - 4*(3)*(280)]}/(2*3) = 2.67 mph
Since her speed on the uphill couldn't be negative the speed on the summit can only be 35 mph.
12 because if you take 2 and add it to 10 you get 12
<u>Answer:</u>
x = ±5
<u>Step-by-step explanation:</u>
We are given the following polynomial function and we are to find all of its real roots:
Let 
so we can now write it as:
Factorizing it to get:
Substitute back to get:
The quadratic factor has only complex roots. Therefore, the real roots are x = ±5.
Answer:
x= -13
y= -28
Step-by-step explanation:
To find the two numbers, write a system of equations with x as one number and y as another:
x-y=15
5x=2y-9
Use substitution to substitute one equation into another. Then solve for the variable.
x=15+y into 5x=2y-9
becomes
5(15+y) = 2y-9
75+5y = 2y- 9
75+3y= -9
3y = -84
y= -28
To find x, substitute y= -28 into one equation.
x - (-28) = 15
x+28 =15
x = 15-28
x=-13
Answer:Titus is going to invest $500. Bank A offers a simple interest rate of 4%, while Bank B offers an interest rate of 3% compounded annually. In the long run, after many years, which bank account will grow the largest?
Step-by-step explanation:
