Answer:
a ≈ 14 or 6
Step-by-step explanation:
264 = π × a × (20 - a)
a(20 - a) =
≈ 84 (rounded off to nearest whole number)
Opening the brackets we get;
a² - 20a + 84 = 0
Applying the quadratic formula we get:
a ≈ 14 or 6
3x^2 = 2(x + 4)
3x^2 = 2x + 8
3x^2 - 2x - 8 = 0
(3x + 4)(x - 2) = 0
3x + 4 = 0
3x = -4
x = -4/3
x - 2 = 0
x = 2
solution is : x = -4/3 or x = 2 <==
She should invest $6491.73.
The equation we use to solve this is in the form

,
where A is the total amount in the account, p is the principal invested, r is the interest rate as a decimal, n is the number of times per year the interest is compounded, and t is the amount of time.
A in our problem is 14000.
p is unknown.
r is 6% = 6/100 = 0.06.
n is 2, since it is compounded semiannually.
t is 13.
9/xy + x^2/y = (9+x^3)/xy
The answer is: "
105 mi. " .
____________________________________________Explanation:____________________________________________Note that: "that amount of time" is "3 hours".
→ 
= ? ;
→ The units of "h" (for "hour/s") cancel out to "1" ; since ("h/h = 1") ;
→ and we are left with (35 * 3) mi.
= 105 mi. ____________________________________________ The answer is: "
105 mi. " .
____________________________________________