Rewrite the fractions to have a common denominator to find the difference:
2/3 = 4/6
Difference = 4/6-5/6 = -1/6
Sequence formula = an = a1 + d(n-1)
A1 is the first term 5/6
And d = -1/6
Sequence = 5/6 -1/6(n-1)
Simplify to get an =(-n +6)/6
1) m∠1 = 360°/8 = 45° . . . . . a regular octagon is 8-way rotationally symmetrical, so each sector is 1/8 of a circle.
2) m∠2 = (180° -45°)/2 = 67.5° . . . . . . the angles of a triangle add to 180°. The base angles of an isosceles triangle are equal.
-7.
5x-3 = -15
-15-4\4= -16
-16 + 9 = -7