Step-by-step explanation:
1.
2.
First equation: Your equation is given.
Second equation: Distribute by multiplying every number in the parentheses by the number outside it.
3rd equation: Combine like terms by adding 4x to both sides.
4th equation: Combine like terms by subtracting 14 from both sides.
5th equation: Divide both sides by -2, the coefficient of x.
Refer to the Attachment.
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Explanation:
Plug n = 6 and r = 5 into the nCr combination formula
Or you could use the shortcut
Yet another path you could take is to use Pascal's Triangle. Locate the row that starts with 1,6,... and then locate the second to last item. That value in the triangle is 6.
A real world interpretation is to consider having 6 people and you are selecting 5 of them to form a group where order doesn't matter. How many ways are there to do this? Well there are 6 such ways because there are 6 ways to leave someone out of the group.
