Question 102639
Let s=how many years there are in a score 



First find the difference between 1863 and 1776


{{{1863-1776=87}}}



So four-score and 7 years is 87 years



So when you say "four-score", you're saying {{{4s}}} and when you add "..and 7 years" you're adding 7 to {{{4s}}} to get:



{{{4s+7}}}



So this means the expression is equal to 87



{{{4s+7=87}}}




{{{4s=87-7}}}Subtract 7 from both sides



{{{4s=80}}} Combine like terms on the right side



{{{s=(80)/(4)}}} Divide both sides by 4 to isolate s




{{{s=20}}} Divide


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Answer:

So our answer is {{{s=20}}}



So this means a score is 20 years