Answer:
5 + sqrt(65), 5 - sqrt(65)
Step-by-step explanation:
x + y = 10
x×y = -40
so, two equations with 2 variables. using one equation to express one variable by the second. and then using the second equation to solve and calculate the second variable. and then by knowing the second variable we calculate the first.
=> x = 10 - y
=> (10-y)×y = -40
=> -1×(10-y)×y = 40
=> (y-10)×y = 40
=> y^2 - 10×y - 40 = 0
remember the solution for a quadratic equation
a×x^2 + b×x + c
is
x = (-b ± sqrt(b^2 - 4×a×c)/(2×a)
in our case
a = 1
b = -10
c = -40
and we used "y".
so,
y = (--10 ± sqrt((-10)^2 - 4×1×(-40))/(2×1) =
= (10 ± sqrt(100 + 160))/2 = (10 ± sqrt(260))/2 =
= (10 ± sqrt (4×65))/2 = 10/2 ± 2×sqrt(65)/2 =
= 5 ± sqrt(65)
=>
for y = 5 + sqrt(65), x = 10 - 5 - sqrt(65) = 5 - sqrt(65)
for y = 5 - sqrt(65), x = 10 - 5 + sqrt(65) = 5 + sqrt(65)
Answer:
15.71
Step-by-step explanation:
Answer:
3 dollars
Step-by-step explanation:
4 goldfish for $2 so 2 goldfish for $1
$1 plus $6 for the two $3 anglerfish
$10 -$7 = $3
The standard deviation of 36,18,12,10 and 9 is 10
Answer:
21
Step-by-step explanation:
The contiguous U.S. consist of all states beside Alaska and Hawaii; therefore, there are 48 contiguous U.S. states. However, the ratio given to us only consists of 16 states [7 + 9 = 16]. If we need to expand the ratio, we multiply 16 by 3 to get 48. Thus, we also multiply each of the terms by 3, and the ratio becomes 21:27. Therefore, the number of contiguous U.S. states that border an ocean is 21.
