Which statement about the supreme court is true and played a role in brown v. board of education?

a.
congress appoints supreme court justices who belong to the majority political party.

b.
the nine justices must always be unanimous in their decisions.

c.
the president can replace justices he doesn't agree with.

d.
a majority of the justices can reverse earlier rulings made by the court.

explanation:

japan participated in world war i from 1914 to 1918 in an alliance with entente powers and played an important role in securing the sea lanes in the west pacific and indian oceans against the imperial german navy as the member of the allies.

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