Question

2. Expand:
(i) (3a +5b)3
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Answer 1

Answer:

here using the property

(a+b)3=a3+b3+2a2b+2ab2

here,a=3a,b=5b

(3a+5b)3=(3a)3+(5b)3+2(3a)2*5b+2*3a(5b)2

=27a3+125b3+2*9a2*5b+2*3a*25b2

=27a3+125b3+90a2b+150ab2

Answer 2

Answer:

$(3a + 5b)^{3} = (3a)^{3} + 3 \times {3a}^{2} \times 5b + 3 \times 3a \times {5b}^{2} + {5b}^{3}$

$= 27 {a}^{3} + 135 {a}^{2} b + 225a {b}^{2} + 125 {b}^{3}$