Question

if the lenght of a rectangle is (2x - 8) cm and the with is (x - 2) cm and the perimeter is 84 cm what is the value of the length ?

Answer 1

Answer:

Step-by-step explanation:

Perimeter = 84 cm

2*(length + width) = 84

2* (2x - 8 + x - 2) = 84

2*(2x + x - 8 - 2) = 84   {bring like terms together}

2*(3x - 10) = 84    {add/ subtract like terms}

Divide both sides by 2

$\frac{2*(3x-10)}{2}=\frac{84}{2}$

3x - 10 = 42

3x - 10 +10 = 42 + 10   {add 10 to both sides}

3x = 52

Divide by 3,

$\frac{3x}{3}=\frac{52}{3}$

x= 17 1/3

Length = 2x - 8

$=2*\frac{52}{3}-8\\\\=\frac{104}{3}-\frac{8*3}{1*3}\\\\=\frac{104}{3}-\frac{24}{3}\\\\=\frac{104-24}{3}\\\\=\frac{80}{3}\\\\=26\frac{2}{3}$