Question

if a+b=c,then show that b^2+ac=c^2-ab

Answer 1

$a + b = c \\ {b}^{2} + ac = {c}^{2} - ab \\ ac + ab = {c}^{2} - {b}^{2} \\ a(b + c) = (c - b)(c + b) \\ a = c - b$
But a+b=c
$a = a + b - b \\ a = a$
LHS=RHS
Hence proved