expand using formula (3x -7y)^3
Answers
Answered by
1
Answer:
(3x - 7y)³ = 27x³ - 343y³ - 189x²y + 441xy²
Step-by-step explanation:
use formula (x-y)³ = x³ - y³ - 3xy(x - y)
(3x - 7y)³ = (3x)³ - (7y)³ - 3 x 3x x 7y( 3x - 7y)
(3x - 7y)³ = 27x³ - 343y³ - 63xy (3x - 7y)
(3x - 7y)³ = 27x³ - 343y³ - 189x²y + 441xy²
Answered by
0
Answer:
( a + b)^3
a^3 +b^3 +3ab (a+b)
a=3 x, b= -7y
therefore,
(3x)^3+(-7y)^3+3(3x)(-7y){3x-7y}
27x^3-343y^3-189x^2y+441 xy^2
hence proved
hope it helps you
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