The number of ways of choosing 4 digits from 10 digits without replacement ( order is important) is 
. This is the number of all possible permutations of choosing 4 from 10. The first 4 numbers of your phone number is a unique 4 digit number(4 different digits). The required probability is
Correct answer: <span>Dot-and-cross-diagram
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Dot-and-cross diagrams are used to represent covalent bonds. The shared electron from one atom is shown as a dot, while the shared electron from the other atom is shown as a cross.
When drawing dot-and-cross diagrams for covalent bonds, you only need to show the electrons in the highest occupied energy level, as only these are involved.
-5 + -40 + -50 = -5 + 8 + 10
-95 = -13
Ether 3 4 Relize To always Look At the equation Of wat You’re Doing
<span>A) 2x - 7y = 13
B) 3x + y = 8
Multiplying equation B by 7
B) 21x + 7y = 56 then adding it to A
</span><span>A) 2x - 7y = 13
23x = 69
x = 3
y = -1
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