Answer:
i) 28 - 30i
ii) 36 + 28i
Step-by-step explanation:
i) x = 6 + i ⇒2x = 2(6 + i) = 12 + 2i
z = 4 - 8i ⇒ 4z = 4(4 - 8i) = 16 - 32i
2x + 4z = (12 + 2i) + (16 - 32i) = 28 - 30i
ii) w = -1 + 5i and z = 4 - 8i
w × z = (-1 + 5i)(4 - 8i) = -4 + 8i + 20i - 40
⇒collect like terms
w × z = -4 + 28i - 40
∵ 
∴w × z = -4 + 28i - 40(-1) = -4 + 28i + 40 = 36 + 28i
Multiply the length*width*height to get the volume of the prism then, take out the difference between the volumes
Volume of the prism= 1018464
Then just subtract
6²+8²=c²
36+64=c²
c²=100
c=10
Answer:
a.) 20 kilometers
b.)1.67 hours
Step-by-step explanation:
a.) formula= speed =distance/time
Speed= 10km/hr
Distance=unknown
Time=2hrs
Therefore from formula, distance=speed x time
10 x 2
20 kilometers
b.) If average speed is increased by 2km/hr then
total speed= 2+10=12km/hr
Distance remains constant therefore distance= 20km
Therefore time =distance/speed
20/12
= 1.67 hours
