Expand: (i) (3/4x+4/5y)^2 (ii)(x/3-4)^2 (iii) (3pq+4r^2)^2 || Find Squares of Each of The Following (i) (3/4x+4/5y) (ii)(x/3-4) (iii) (3pq+4r2) [S.Chand Class 9 ICSE Fundamentals of Mathematics Chapter 3 Exercise 3.1 Expansion and Factorisation Solution]
(i) (3/4x+4/5y)^2
= $\left(\frac{3}{4{\mathrm{x}}} + \frac{4}{5{\mathrm{y}}}\right)^2$
= $\left(\frac{3}{4{\mathrm{x}}}\right)^2 + 2.\left(\frac{3}{4{\mathrm{x}}}\right)\ldotp \left(\frac{4}{5{\mathrm{y}}}\right) + \left(\frac{4}{5{\mathrm{y}}}\right)^2$
= $\frac{9}{4{\mathrm{x}}^2} + \frac{6}{5{\mathrm{xy}}} + \frac{16}{25{\mathrm{y}}^2}$ [Ans]
(ii) $\left(\frac{{\mathrm{x}}}{3} – 4\right)^2$
= $\left(\frac{{\mathrm{x}}}{3}\right)^2 – 2.\frac{{\mathrm{x}}}{3}\ldotp 4 + (4)^2$
= $\frac{{\mathrm{x}}^3}{9} – \frac{8{\mathrm{x}}}{3} + 16$ [Ans]
(iii) (3pq+4r2)2
= (3pq)2 +2(3pq)(4r2)+(4r2)2
=9p2q2 +24pqr2+16r4 [Ans]