-Not to make impulse buys
-Open a savings account that directly adds a set amount of money into it from your paycheck monthly
-The '50-30-20' rule(<span>50 percent of your income toward necessities, like housing and bills. Twenty percent should then go toward financial goals, like paying off debt or </span>saving<span> for retirement. Finally, thirty percent of your income can be allocated to wants, like dining or entertainment.)</span>
-Create a budget
Answer: I think it's D.
Explanation: I'm sorry if I chose the wrong answer, I'm not too good with stuff like this.
<u><em>Answer:</em></u>
<u><em>The speed is </em></u>
<u><em>=
</em></u>
<u><em>30
</em></u>
<u><em>m
</em></u>
<u><em>s
</em></u>
<u><em>−
</em></u>
<u><em>1
</em></u>
<u><em>
</em></u>
<u><em>Explanation:
</em></u>
<u><em>The speed of a wave is given by
</em></u>
<u><em>
</em></u>
<u><em>speed
</em></u>
<u><em>(
</em></u>
<u><em>m
</em></u>
<u><em>s
</em></u>
<u><em>−
</em></u>
<u><em>1
</em></u>
<u><em>)
</em></u>
<u><em>=
</em></u>
<u><em>frequency(Hz)
</em></u>
<u><em>×
</em></u>
<u><em>wavelength (m)
</em></u>
<u><em>
</em></u>
<u><em>The frequency is </em></u>
<u><em>f
</em></u>
<u><em>=
</em></u>
<u><em>100
</em></u>
<u><em>H
</em></u>
<u><em>z
</em></u>
<u><em>
</em></u>
<u><em>The wavelength is </em></u>
<u><em>λ
</em></u>
<u><em>=
</em></u>
<u><em>0.3
</em></u>
<u><em>m
</em></u>
<u><em>
</em></u>
<u><em>The speed is
</em></u>
<u><em>
</em></u>
<u><em>v
</em></u>
<u><em>=
</em></u>
<u><em>λ
</em></u>
<u><em>f
</em></u>
<u><em>=
</em></u>
<u><em>0.3
</em></u>
<u><em>⋅
</em></u>
<u><em>100
</em></u>
<u><em>=
</em></u>
<u><em>30
</em></u>
<u><em>m
</em></u>
<u><em>s
</em></u>
<u><em>−
</em></u>
<u><em>1
</em></u>
<u><em>
</em></u>
<u><em></em></u>
<u><em></em></u>
<u><em></em></u>