Your friend solved 7.15 + (-12.76) = 19.91. Are they correct? Explain your reasoning.

he is not correct

correct answer is -5.61

Step-by-step explanation:

he added them together but did not account for the negative in the second term

they are not correct because 7.15 + (-12.76) equals −5.61 not 19.91

Step-by-step explanation:

hope this helps

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

could

step-by-step explanation:

u send me a picture of ur work