Rate me.1-10?!?!?! (Dark hair)

Which value is not a solution of 8x^3 – 1 = 0

What is the perimeter of trapezoid jklm? + units 2 + + units 9 + units 9 + + units

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is