Question

E 4) In the diagram below, the dimensions of the large rectangle are (3x-1) by (3x+7) units. The dimensions of the cut-out rectangle are x by (2x+5) units. Which choice expresses the area of the shaded region, in Square units? ​

Answer 1

Answer:

Option (D)

Step-by-step explanation:

Area of a rectangle = Length × width

Area of large rectangle = (3x - 1)(3x + 7) square units

                                       = (9x² + 21x - 3x - 7)

                                       = 9x² + 18x - 7

Area of small rectangle = (2x + 5)x

                                       = (2x² + 5x) square units

Area of the shaded region = Area of large rectangle - Area of small rectangle

= (9x²+ 18x - 7) - (2x² + 5x)

= (9x² - 2x²) + (18x - 5x) - 7

= (7x² + 13x - 7) square units

Therefore, Option (D) will be the correct option.