Which of these systems of linear equations has an infinite number of solutions?

a. 3x-8y=21
6x-16y=46

b. 3x+6y=22
6x+12y=44

c. 5x+9y=2-
10x-14y=48

d. 5x-9y=20
10x+18y=40

∆red ≅ ∆ by rule will give brainiest if possible

The length of an intercepted arc of a central angle of a circle is 4 cm. if the radius of the circle is 5 cm what is the measurement of the central angle to the nearest whole degree

Someone answer this asap for the first five terms of a sequence are shown. 5, 11, 23, 47, 95, . . which recursive function defines the nth term in the sequence for n > 1? a. f(n) = f(n - 1) + 6 b) f(n) = f(n - 1) + 48 c) f(n) = 3 • f(n - 1) + 1 d) f(n) = 3 • f(n - 1) - 4