Solve each proportions: 1) 7/2 = a/5

2) 8/r = 9/7

3) 6/b = 7/5

PLEASE HELP!

Can someone answer this question? : )

Find the area of the regular hexagon if a side is 20 cm.

What is the explicit formula for this sequence? -7, -4, -1, 2, a.) an = 8 + (b - 1)3 b.) an = -7 + (n - 1)3 c.) an = 3 + (n -1) (-7) d.) an = -7 + (n - )