Write about the history of algebra. How did our knowledge of Algebra evolve? Who were some of the greatest mathematicians who contributed to this knowledge? Help pls​

If the graphs of the linear equations in a system are parallel, what does that mean about the possible solution(s) of the system? a. there are infinitely many solutions. b. there is no solution. c. there is exactly one solution. d. the lines in a system cannot be parallel.

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

Si la base de un triángulo isósceles mide 70 m y el ángulo opuesto a ésta mide 58°; entonces ¿cuánto mide la altura de dicho triángulo? a) 21.87 m. b) 40.01 m. c) 43.74 m. d) 63.14 m.