Can you please answer the last question, i really need help and please explain thank you

x3, +1

Step-by-step explanation:

To go from x to 3x +1, we need to multiply by 3 and add 1. However, the order is important! Think back to PEMDAS, BIDMAS or any equivalent, we know that multiplication goes before addition, and so x3 happens first. To double check, let's have a look at an example, and use x = 2, and so 3x+1 becomes 7.

If we add first, we get 2+1 = 3, and then when we multiply, we get 3x3=9, which isn't correct.

If we multiply first, we get 3x2=6, and then 6+1=7

Hope I helped! xx

true

step-by-step explanation:

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!