A scale has a percent error of 7%. The scale reads the mass of a book as 450 g. Which statement describes what the actual mass of the book could be?

The actual mass is either 453 or 447

Step-by-step explanation:

7 percent of 450

= (7/100) * 45

= 3.15

error = 3.15 g

hence actual mass

= 450 + 3.15

= 453.15

or

= 450 - 3.15

= 446.85

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!