<span>1. </span><span>Given numbers
=> 7 centimeters convert to meters
In every 1 meter there are 100 centimeters
=> 7 / 100
=> 0.07
Therefore in 7 centimeters there are 0.07 meters.
7 cm is a whole number while 0.07 m is a decimal number
Scientific Notation of each numbers
=> 7 cm = 7 x 10^0
=> 7 m = 1 x 10^-2
Scientific notation by the way is an expression used by the scientist to make a
large number or very small number easy to handle.
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Let x be your first alloy
2/5x+7/10(30-x)=1/2(30)
4x+210-7x=150
3x=60
x=20
So, you need 20 lbs of the first alloy, and 10 parts of the second to make 30 lbs of half iron and half silver alloy!
Do you have a picture or sum?
Your answer would be the last option, 80 cm.
As this is a right triangle, you can use Pythagoras's Theorem, a² + b² = c², where 'c' is the hypotenuse and 'a' and 'b' are the legs, to find the missing side.
This gives us:
48² + 64² = 2,304 + 4,096 = 6,400
√6,400 = 80
So 80 is your answer.
I hope this helps!