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Answer:
V= 105cm^3
Step-by-step explanation:
V=volume
(1/3)V+40=(5/7)V
(5/7)V-(1/3)V=40
(15/21)V-(7/21)V=40
(8/21)V=40
(21/8)(8/21)V=(21/8)(40
V=21*5
V=105 cm3
(1/3)(105)=35, 35+40=75, 75/105=15/21=5/7
Question 7:
Diameter = 6.2 cm so Radius = 3.1 cm
A=πr² = 3.14 × 3.1² = 30.1754 cm² = 30.18 cm²
Question 8:
Circumference = 2πr
16π = 2πr
therefore 16 = 2r so r = 8cm
U=2x+3, x=u/2-3/2
u^2+8u+11=0
u1=(-8+sqrt(64-44))/2=-4+sqrt(5)
u2=-4-sqrt(5)
x1=u1/2-3/2=-7/2+sqrt(5)/2
x2=u2-3/2=-7/2-sqrt(5)/2
Answer:
the answer is the first choice .