Solve:
(i) 16x2−20x+98x2+12x+21=4x−52x+3
(ii) 5y2+40y−125y+10y2−4=y+81+2y
(i) 16x2−20x+98x2+12x+21=4x−52x+3
Let, k=16x2−20x+98x2+12x+21=4x−52x+3
Multiplying numerator and denominator of 4x−52x+3, we get,
⇒16x2−20x+98x2+12x+21=4x(4x−5)4x(2x+3)
⇒16x2−20x+98x2+12x+21=16x2−20x8x2+12x
Using Theorems on Equal ratios ie. ab=cd=a−cb−d, we get,
⇒16x2−20x+98x2+12x+21=16x2−20x8x2+12x=16x2−20x+9−16x2+20x8x2+12x+21−8x2−12x
⇒k=921=37
Hence, 16x2−20x+98x2+12x+21=4x−52x+3=37
(ii) 5y2+40y−125y+10y2−4=y+81+2y
Let, z=5y2+40y−125y+10y2−4=y+81+2y
Multiplying numerator and denominator of y+81+2y by 5y, we get,
⇒5y2+40y−125y+10y2−4=5y(y+8)5y(1+2y)
⇒5y2+40y−125y+10y2−4=5y2+40y5y+10y2
Using Theorems on Equal ratios, we get,
⇒5y2+40y−125y+10y2−4=5y2+40y5y+10y2=5y2+40y−12−5y2−40y5y+10y2−4−5y−10y2
⇒z=−12−4=3
Hence, 5y2+40y−125y+10y2−4=y+81+2y=3