Please answer and show your work, thank you.

11.) 7a - 4a = 24      12.) 1800    13.)  5.4     14.) 3.55   15.) 35     16.) 99.32

Step-by-step explanation:

11.)        7(8) - 4(8)

 7 x 8 = 56 ) ( 4 x 8 = 32

          56 - 32 = 24

12.)  15 x 12 = 180

     180 x 10 = 1800

13.)  7.8 − 2.4  = 5.4

14.)   Move the decimal two spaces to the left

        355% = 3.55

15.)  A=hbb

      2=5·14

        2=35

16.)   54.2

        19

    +  26.12

         99.32

answer: yes, he is correct

step-by-step explanation: 10x-1=59

                                              1-1=0     59+1=60

60/10=x=6

definition: a circle is the  set of all points in a plane that are equidistant  from a given  point  called the center of the circle. we use the symbol ⊙ to represent a circle. the a line segment from the center of the circle to  any point  on the circle is a radius of the circle.

step-by-step explanation:

i googled it and this is what i got i don't know how it is. sorry.