Jillian simplified the expression 7 + 3 . (10 -6) ^2 in the following way: 7 + 3 . (10 - 6) ^2
7+ 3 . (4)^2
7+3 . 16
10 . 16
160

Part: A Explain, using the complete sentences, what Jillian’s error was

Part B: show how the expression should have bee simplified using a similar format.

Please help me how should I explain it

Part A: Jillian added 7+3 first rather than multiplying 3*16 b/c multiplication comes before addition

Part B:

7 + 3 * (10 - 6) ^2

7+ 3 * (4)^2

7+3 * 16

7 + 48

55

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!