Simone wrote that 2 + 5.8 = 6.

Use the drop-down menus to explain why 6 is incorrect.

7.8

0.2

Step-by-step explanation:

2 is in the ones place, to get to six you need the value of 2 in the tenths place (0.2)

2+5.8 is 7.8 (add the ones places together to get 7)

0.2+5.8=6 (add in the tenths place)

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb