Which Excel feature is used to create drop-down lists in

3^x +3^y =10 and 3^x+y =5 then find the value of 3^x-y +3^y-x.

If, 3x + 2y = 15, and 2xy = 12, and 3x > 2y, then find the value of 27x³ – 8y³.

1/3 + 1/15 + 1/35 + 1/63 + 1/99 = ?

If sin 28° = 15/17 , then tan 62° = ?

(m + 2) ² + (n - 1) ² + (p + 6) ² = 0, then find the value of 2m - 3n + p.

Find the value of ‘x’ in the given expression:

(49/16)^x × (64/343)^x-1 = 4/7

If x = (√13 + √12)/ (√13 - √12) and y = (√13 - √12)/(√13 + √12), then find the value of 4x² – xy + 4y².

If x ,y,z are three integers such that x +y = 8,y +z =13 and z +x =17,then the value of x² /yz   is:

If 9x² + y² = 37 and xy=2, x, y>0, then the value of (27x³ + y³) is:

If x + y + xy = 118, such that x < y and both 'x' and 'y' are positive integers, then find minimum value of (x + y) .