Answer:
4 months
Step by step explanation
If you subtract 30 by 2 for 4 months you get 22 and if you add 4 4 times to 6 you get 22 and that means the answer is 4 months.
6:20=9:30=3:10=18:60=16:160/3=12:40
Step-by-step explanation:
The question requires you to find value of x in the ratios given;
Start with the first pair
6:20 = 9:x
6/20 =9/x
6x=20*9
6x=180
x=180/6=30 ⇒⇒ 6:20 = 9:30
The second pair after replacing the value of x=30 will be
9:30 = x:10
9/30=x/10
90=30x
90/30 =x
3=x⇒⇒ 9:30 = 3:10
The third pair after replacing value of x=3 will be
3:10 =x:60
3/10 =x/60
180=10x
180/10 =x
18=x ⇒⇒ 3:10 = 18:60
The fourth pair after replacing value of x=18 will be;
18:60 = 16:x
18/60 = 16/x
18x=16*60
x= (16*60)/18 =160/3
x= 160/3 ⇒⇒⇒ 18:60 = 16: 160/3
The firth pair after replacing value of x=160/3 will be;
16: 160/3 =12:x
16x= 160/3 *12
16x = 160 * 4
x= (160 *4 )/16
x=40
⇒⇒ 16: 160/3 = 12: 40
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Ratios and proportions :brainly.com/question/9512748
Keywords : ratio, value of x, proportion
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Answer:
A(n)= 100 + (n-1)4
Step-by-step explanation:
Answer:
2.29 ft of side length and 1.14 height
Step-by-step explanation:
a) Volume V = x2h, where x is side of square base and h is hite.
Then surface area S = x2 + 4xh because box is open.
b) From V = x2h = 6 we have h = 6/x2.
Substitude in formula for surface area: S = x2 + 4x·6/x2, S = x2 + 24/x.
We get S as function of one variable x. To get minimum we have to find derivative S' = 2x - 24/x2 = 0, from here 2x3 - 24 = 0, x3 = 12, x = (12)1/3 ≅ 2.29 ft.
Then h = 6/(12)2/3 = (12)1/3/2 ≅ 1.14 ft.
To prove that we have minimum let get second derivative: S'' = 2 + 48/x3, S''(121/3) = 2 + 48/12 = 6 > 0.
And because by second derivative test we have minimum: Smin = (12)2/3 + 4(12)1/3(12)1/3/2 = 3(12)2/3 ≅ 15.72 ft2
