Which of the following dates is incorrect? a. Between 1852 and 1853, the first rail lines were constructed in Texas. b. The Mexican Railway was completed in 1869. c. The steam engine was greatly improved by Scottish inventor James Watt in 1769. d. Abraham Lincoln signed the Pacific Railroad Act on July 2, 1862.

a. Between 1852 and 1853, the first rail lines were constructed in Texas.

b. The Mexican Railway was completed in 1869.

d. Abraham Lincoln signed the Pacific Railroad Act on July 2, 1862.

Explanation:

The first rail lines were built in 1851, while the first locomotive passed across this rail in 1852. The largest portion of Mexican Railway was built in 1873. Abraham Lincoln signed the Pacific Railroad Act a day earlier, on July 1, 1862.  James Watt improved steam engine in 1769 and that is the only correct date.

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.