What is the surface area of a right cone with a height of 12.9 and a diameter of 10.2

option 3 . (5x + 1) - (-10x + 6)

step-by-step explanation:

option 1 :

(4x + 3) + (-9x + 4)

or 4x+3 -9x + 4

or -5x + 7

option 2

(x - 2) - (6x - 9)

or x-2-6x + 9

or -5x + 7

option 3

(5x+ + 6)

or 5x + 1 + 10x -6

or 15x -5

option 4

-4x+2x+7-3x

-7x + 2x + 7

-5x + 7

hence only option 3 did   not satisfy the given simplify expression.

the correct answer option is d. la = πrs.

step-by-step explanation:

we know that for a right cone, the lateral surface area is given by:

lateral area of right cone =

here the value under the square root is equal to slant height so replacing this value by in the formula to get:

lateral area of right cone =

therefore, the correct answer option is d.