What two properties of a Cepheid variable star do we need to know in order to calculate the approximate distance from Earth?
1 answer:
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Answer:
Michael worked 4 hours and Landon worked 10 hours.
Step-by-step explanation:
Michael can iron 40 shirts each hour, so in xx hours he can iron 40x40x shirts. Landon can iron 20 shirts each hour, so in yy hours he can iron 20y20y shirts. The total number of shirts ironed 40x+20y equals 360:
40x+20y=360
40x+20y=360
Since Michael and Landon worked a combined 14 hours, we know x+yx+y must equal 14.
x+y=14
Write System of Equations:
40x+20y= 360
x+y=14
Solve for y in each equation:
40x+20y = 360 x+y = 14 20y = -40x+360
=
y = -2x+18
Answer: OPTION D.
Step-by-step explanation:
The formula for calculate the circumference of a circle is:
Where <em>r</em> is the radius.
The formula for calculate the area of a circle is:
Where <em>r</em> is the radius.
Solve for <em>r</em> from to calculate it:
Subsitute the radius into . Then: