You're trying to find constants

such that

. Equivalently, you're looking for the least-square solution to the following matrix equation.

To solve

, multiply both sides by the transpose of

, which introduces an invertible square matrix on the LHS.

Computing this, you'd find that

which means the first choice is correct.
Q in (-oo:+oo)
2/3 = (1/3)*q // - (1/3)*q
2/3-((1/3)*q) = 0
ddddddddd
d d
d d
(-1/3)*q+2/3 = 0 d d
d d
2/3-1/3*q = 0 // - 2/3 d d
d d
-1/3*q = -2/3 // : -1/3 d d
d d
q = -2/3/(-1/3) ddddddd dddddddd
dd dd
q = 2 dd dd
dd dddd dd
q = 2 dddddddddd dddddddddddd
2 is the max number because it's one less than the degree
Answer:
$3.48 for each pair of socks.
Step-by-step explanation:
It's a little confusing, because it says they're buying 2 socks, but then asks for the price of each of 2 *pairs* of socks. I'm going to believe the first sentence should say they paid for 2 pairs of socks.
They have $10, and get $3.04 in change. So we'll subtract $3.04 from $10 to find out the cost of 2 pairs of socks.
10 - 3.04 = 6.96
Then divide $6.96 by 2 pairs of socks
6.96/2 = $3.48 for each pair of socks.
-- 500 centimeters = 5 meters
-- 0.005 kilometers = 5 meters
-- 5,000,000,000 nanometers = 5 meters