Question

Ifa, b, c and d are in continued proportion, prove that :
(a +d) (b + c) - (a + c)(b + d) = (b -c)².​

Answer 1

$\huge \mathbb\fcolorbox{black}{lavender}{Answer♡}$

Step-by-step explanation:

(a +d)(b+c)-(a+c)(b+d)

a(b+c)+d(b+c)-[a(b+d)+c(b+d)]

ab +ac+bd+cd-[ab+ad+cb+cd]

ab+ac +bd +cd-ab-ad-cb-cd

ac +bd -ad-cd

ac -ad +bd-cd

a(c-d)+d(b-c)