Need to find shaded area of figure please help!

39 ft^2

Step-by-step explanation:

Find the area of the triangle and subtract the area of the square.

area of triangle = bh/2

area of square = s^2

shaded area = bh/2 - s^2

shaded area = (20 ft)(16 ft)/2 - (11 ft)^2

shaded area = 160 ft^2 - 121 ft^2

shaded area = 39 ft^2

- 2 + 10x³ - 21x² + 19x - 4

step-by-step explanation:

each term in the second factor is multiplied by each term in the first factor

x²(- 2x² + 4x - 1) - 3x(- 2x² + 4x - 1) + 4(- 2x² + 4x - 1) ← distribute

= - 2 + 4x³ - x² + 6x³ - 12x² + 3x -8x² + 16x - 4

collect like terms

= - 2 + 10x³ - 21x² + 19x - 4 ← in standard form