Question

Escreva o Cubo da soma e o da diferença
a) (10x+z)³ b) (2a-y)³

Answer 1

a) (10x + z)³

Fórmula: (a + b)³ = a³ + 3a²b + 3ab² + b³

a = 10x          b= z

10³x³ + 3.100x².z + 3.10x.z² + z³
1000x³ + 300x²z + 30xz² + z³

b) (2a - y)³

Fórmula: (a - b)³ = a³ - 3a²b + 3ab² - b³
a = 2a         b= y

8a³ - 3.4a²y + 3.2ay² - y³

8a³ - 12a²y + 6ay² - y³

Answer 2

a) (10x+z)³ = (10x)³ + 3.(10x)².z +  3.(10x).z² + z³

1000x³ + 3.(100x²).z +  30x.z² + z³ ==> 1000x³ + 300x².z +  30x.z² + z³
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b) (2a-y)³ = (2a)³ + 3.(2a)²(-y) +  3.(2a).(-y)² + y³

8x³ + 3.(4a²).(-y) +  6ay² + y³ ==> 8x³ - 12a²y +  6ay² + y³