Math. F.1

a)The width
=(x-7)cm

b)The perimeter
[x+(x-7)]2=74

c)Let the length of a rectangle is x
[x+(x-7)]2=74
(x+x-7)2=74
(2x-7)2 =74
4x-14=74
4x=74+14
4x=88
x=22
The length of a rectangle is 22 cm

The length of a rectangle is x cm .

a) The length is 7 cm longer than the width . Express the width in terms of x

b) The perimeter is 74 cm . Write down an equation in x .

c) Slove the equation in (b) .Hence fin d the dimensions of the rectangle.

x=22

22cm * 15cm = 330cm^2

a. (x-7) cm

b. 2*x+2*(x-70

c. x=22, dimensions = 22*22+15*15= 709's square root = 26.6270539113................................................. to the nearest whole number is 27

2009-07-18 10:29:13 補充：
new information
c. x=22, dimensions means the area ,so should be 22*(22-7)= 22*15=330