How many dominoes are in there??

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

Acone with volume 1350 m³ is dilated by a scale factor of 1/3. what is the volume of the resulting cone? enter your answer in the box. m³

Which shows the correct substitution of the values a,b and c from the equation 1=-2x+3x^2+1