Which expression is equivalent to a+ a+ a+ b+ b+ b

Arunning track in the shape of an oval is shown. the ends of the track form semicircles. a running track is shown. the left and right edges of the track are identical curves. the top and bottom edges of the track are straight lines. the track has width 56 m and length of one straight edge 130 m. what is the perimeter of the inside of the track? (π = 3.14) 260.00 m 347.92 m 372.00 m 435.84 m

4. a spring scale is constructed so that each 0.10-n increment is separated by 0.50 cm. what spring constant is necessary for the scale to be accurate? -1.0n/cm -0.10n/cm -9.8 n/cm -0.20n/cm

Marcus needs to rewrite f(x) = x2 + 6x + 4 in vertex form.