Question

if a+b=1 , c+d=1 and a-c=d/c then the value of (c+d)(c-d)

Answer 1

a-b)=d/c

(a+b)=1

so dividing (1) by (2)

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

applying componendo and dividendo rule

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

a/b=1/(c-d)

(c-d)=b/a …………(A)

(c+d)=1 …………….(B)

multiplying both (A) and(B)

c^2-d^2=b/a.1=b/a

HOPE IT IS HELPFUL