Question 530107
Can you please help me on this question: If the width of a rectangle is (x+7) cm and its perimeter is (8x + 12)cm. The length of the rectangle is 20cm. What is the area of the rectangle?.
since 
perimeter = 2(width + length)
8x+12 = 2(x+7 + 20)
8x+12 = 2(x+27)
4x+6 = x+27
3x+6 = 27
3x = 21
x = 7
.
Now, we can calculate width:
x+7 = 7+7 = 14 cm
.
area:
width*length
14*20 = 280 square cm