Answer:
C. O.5s
Step-by-step explanation:
If the wave length is 100m and it goes at a speed of 200m/s then it will only take 0.5 seconds because 100 is half of the speed of 200
We calculate the commission and adding it to the price of the stock to get total cost.
No Price Total Commission Total cost
100 $26.25 0.06 x $2,625 = $157.50 2625 + 157.50 =2782.5
100 $19.32 0.06 x $1,932 = $115.92 1932 + 115.92 =2047.92
40 $9.77 0.06 x $390.80 = $23.45 390.80 + 23.45= 414.25
200 $5.39 0.06 x $1,078 = $64.68 1,078 + 64.68 = 1142.68
100 $33.44 0.06 x $3,344 = $200.64 3,344 + 200.64 = 3544.64
\begin{gathered}\{\begin{array}{ccc}3x+5y=2&|\cdot(-3)\\9x+11y=14\end{array}\\\underline{+\{\begin{array}{ccc}-9x-15y=-6\\9x+11y=14\end{array}}\ \ |\text{add both sides of equations}\\.\ \ \ \ \ -4y=8\ \ \ |:(=4)\\.\ \ \ \ \ y=-2\\\\\text{substitute the value of y to the first equation}\\\\3x+5\cdot(-2)=2\\3x-10=2\ \ \ |+10\\3x=12\ \ \ |:3\\x=4\\\\Answer:\ x=4;\ y=-2\to(4;\ -2)\end{gathered}
{
3x+5y=2
9x+11y=14
∣⋅(−3)
−9x−15y=−6
9x+11y=14
add both sides of equations
. −4y=8 ∣:(=4)
. y=−2
substitute the value of y to the first equation
3x+5⋅(−2)=2
3x−10=2 ∣+10
3x=12 ∣:3
x=4
Answer: x=4; y=−2→(4; −2)
