Answer:
C. 3(x + 5)
Explanation:
area of rectangle = length * width = width * length
A = area of largest rectangle
a1 = area of left rectangle
a2 = area of right triangle
The largest rectangle is made up of the the two smaller rectangles.
A = a1 + a2
Left rectangle: a1 = WL = 3x
Right rectangle: a2 = WL = 3 * 5
Total area of the two small rectangles:
A = a1 + a2 = 3x + 3 * 5
Apply the distributive property in reverse to 3x + 3 * 5 by factoring out a 3:
A = 3x + 3 * 5 = 3(x + 5)
The area of the largest rectangle is 3(x + 5)
We can also find an expression for the area of the largest rectangle directly by looking at its length and width.
The length of the largest rectangle is x + 5.
The width of the largest rectangle is 3.
A = WL
Substitute 3 for W, the width.
Substitute x + 5 for L, the length.
A = 3(x + 5)
Answer: C. 3(x + 5)