Question

a rectangular wall with a length of 10x and width of 20 x has a rectangular doorway with a length of 5x and a width of 2x. What is the surface area of the wall?

Answer 1

Answer:

∴ The the surface area of the wall is $190x^{2} \ square\ unit$.

Step-by-step explanation:

Given that,

                 The length of rectangular wall is $10x$.

                 The width of rectangular wall is $20x.$

                 The length of doorway is $5x.$

                 The width of doorway is $2x.$

and, we have to find the surface area of rectangular wall.

Now,

The length of rectangular wall is $10x$.

The width of rectangular wall is $20x.$

∴ Total surface area of a rectangular wall $= Length\ of\ wall\times Width\ of\ wall$

                                                                     $= 10x\times 20x$

                                                                     $=$ $200x^{2} \ square\ unit$

Total surface area of a rectangular wall is $200x^{2} \ square\ unit$.

Again, The length of doorway is $5x.$

           The width of doorway is $2x.$

∴Total surface area of doorway $=Lenght\ of\ doorway\times Width\ of\ doorway$

                                                     $=5x\times 2x$

                                                     $=10x^{2} \ square\ unit$

Total surface area of doorway is $10x^{2} \ square\ unit$.

∴The remaining surface area of a rectangular wall is $=$ $200x^{2} -10x^{2}$                                                                                                        

                                                                                           $=190x^{2} \ square\ unit$

∴ The the surface area of the wall is $190x^{2} \ square\ unit$.