Which addition does the model below represent? 3 + (negative 1)
3 + 4
3 + (negative 4)
3 + 1

The correct answer is 3 + -4.

Step-by-step explanation:

First the arrow begins at 0 and moves to the right 3 spaces positive, ending at 3. Then it moves backwards, which is subtracting left 4 spaces towards -1 past zero. When adding a negative to a positive, you convert it to subtraction. 3 + -4 is the same as 3 - 4. We know 4 - 3 normally is 1, but the other way around, since 4 is more than 3, we go one extra space negative to -1. Therefore, 3 + -4 is the answer.

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!