The length of a rectangle is 5 centimeters less than twice its width. the perimeter of the rectangle is 26 cm. what are the dimensions of the rectangle?
a)length = 5 cm; width = 5 cm
b)length = 6 cm; width = 7 cm
c)length = 4 cm; width = 9 cm
d)length = 7 cm; width = 6 cm

Let w and l be the length and height of the rectangle.

We know that:

Substitute the first equation in the second:

Use the first equation to compute the length:

So, length = 7 cm; width = 6 cm

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.