Answer:
-8i
Step-by-step explanation:
To multiply numbers is polar form
z1 = r1 ( cos theta 1 + i sin theta 1)
z2 = r2 ( cos theta 2 + i sin theta 2)
z1*z2 = r1*r2 (cos (theta1+theta2) + i sin (theta1+theta2)
z1 = 2(cos 70° + i sin 70°)
z2 = 4(cos 200+ i sin 200)
z1z2 = 2*4 (cos (70+200) + i sin (70+200)
z1z2 = 8 (cos(270) + i sin (270))
= 8 (0 + i (-1))
=-8i
<span><u><em>Answer:</em></u>
(5 * 1) + (9 * 0.1).<span>
<u><em>Explanation:</em></u>
To write a number in expanded form you have each digit multiplied by its numbers place and add each digit together. 5 is in the ones place so it becomes (5 * 1).
9 is in the tenths place so it becomes (9 * 0.1).
add them together to get (5 * 1) + (9 * 0.1)</span></span>
Answer:
thr answer is C.
Step-by-step explanation:
because the time was already 3 hours and there were already 12 gallons of water
