a solid shape is made by joining two cones. each one has the same radius. one cone has slant height=2 x radius the other cone has slant height= 3 x radius the total surface area of the shape is 135.2pie cm^2 curved surface area of a cone= pierl where r is the radius and l is the slant height. work out the radius.

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

ou would have 12 of each

b

step-by-step explanation:

u take $75 minus $60.the anwer/original($75)multiply by 100