The first african american to serve in congress was
ebenezer d. bassett.
francis cardozo.
blanche bruce.
hiram revels.

Hiram Revels

Explanation:

Hiram Revels and Joseph Rainey were the first two African americans to serve in congress

answer: this problem has only trivial solutions, with all points on the same line. x=5 or x=7/5.

step-by-step explanation:

there are three triangles, and three unknowns: x, y=length of middle segment, and z=cos(angles marked with red arc).

we need

and law of cosines,

the three equations are

see attached image for solution.

the indians crossed artificial boundaries, setting the stage for conflict