2x^2 + 16x - 10 = 0
2(x^2 + 8x) - 10 = 0
2 [(x + 4)^2 - 16 ]- 10 = 0
[(x + 4)^2 - 16 - 5 = 0
(x + 4)^2 - 21 = 0
(x + 4)^2 = 21
It would be 78/4=19.5 which would mean that he would be able to set 19 tables. To be able to set all of the tables he would need 2 more napkins because 19*4=76. 78-76=2 so they would need 2 more to finish the last table.
Answer:
r^2 + 14r + 33
Step-by-step explanation:
Apply the "FOIL" method for multiplying two binomials:
(r+3) (r+11) = r^2 (first terms) +
+ 33 (last terms) +
+ 11r (outer terms) +
+ 3r (inner terms)
Combining ilke terms, we get:
r^2 + 14r + 33
Alright, so here we have a cone and a cylinder. The cone has a height of 12. The cylinder has a height of 10.5. Both shapes, because they're on top of each other, have a diameter of 26 or a <em>radius</em> of 13.
Equation for a cylinder: 
Equation for a cone: 
We're going to add both of the volumes of these shapes as soon as we find them.
Cylinder:

Cone:

Add both values: 2123.717 + 5574.756 = 7698.473 cm³.
Hope this was helpful, let me know if I missed anything!