Who was emmet till and why was he killed?

In 1945 a few weeks before his son's fourth birthday he was executed for the ra pe and murder of an italian woman  at the age of six emmett contracted polio which left him with a persistent stutter

increases in demand are shown by a shift to the right in the demand curve. this could be caused by a number of factors, including a rise in income, a rise in the price of a substitute or a fall in the price of a complement.

which the answer is:

b

the perimeter of a triangle is 69 cm. side a is 5 cm shorter than side b. side c is twice as long as side a. find the length of each side. i need to know how to do it in 2 equations.  

equations:

a = b-5

c = 2a

a + b + c = 69