PLZ HELP ME OUT WITH THIS

B. 25√3

Step-by-step explanation:

Use trigonometric ratio formula to find the length and width of the rectangle

Thus:

✔️Length of diagonal:

Reference angle = 30°

Hypotenuse = 10

Let length of rectangle = x = adjacent side

Therefore:

Cos 30° = x/10

10*cos 30 = x

10*√3/2 = x (cos 30 = √3/2)

5√3 = x

x = length of rectangle = 5√3

✔️Width of diagonal:

Reference angle = 30°

Hypotenuse = 10

Let width of rectangle = y = opposite side

Therefore:

Sin 30° = y/10

10*sin 30 = y

10*½ = y (sin 30 = 1/2)

5 = y

y = width of rectangle = 5

✔️Area of rectangle = length * width = 5√3 * 5 = 25√3

-2

7 - 9 = -2

reversed:

-2 + 9 = 7

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!