Which placement of grouping symbols in the expression gives it a value of 6?
7 • 5 – 4 • 5 + 9
a.
7 • (5 – 4) • (5 + 9)
b.
7 • [(5 – 4) • 5] + 9
c.
7 • [5 – (4 • 5) + 9]
d.
(7 • 5) – [(4 • 5) + 9]

Abicycle training wheel has a radius of 3 inches. the bicycle wheel has a radius of 10 inches.approximately how much smaller, in square inches and rounded to the nearest hundredth, is the area of the training wheel than the area of the regular wheel? *