Question

5. Раскрыть скобки: a) (5-a)3 6) (2x+6y)³​

Answer 1

Ответ:

а) 15-3а

б) 8х^3+72х^2у+216ху^2+216у^2

Answer 2

a) (5 - a)3

To expand the expression (5 - a)3, we can use the binomial expansion or the distributive property. Let's use the distributive property to expand it:

(5 - a)3 = 3 * (5 - a) = 3 * 5 - 3 * a = 15 - 3a

Therefore, the expression (5 - a)3 expands to 15 - 3a.

b) (2x + 6y)³

To expand the expression (2x + 6y)³, we can use the binomial expansion. The binomial expansion of (a + b)³ is given by:

(a + b)³ = a³ + 3a²b + 3ab² + b³

Applying this formula to our expression, where a = 2x and b = 6y, we get:

(2x + 6y)³ = (2x)³ + 3(2x)²(6y) + 3(2x)(6y)² + (6y)³ = 8x³ + 3(4x²)(6y) + 3(2x)(36y²) + 216y³ = 8x³ + 72x²y + 216xy² + 216y³

Therefore, the expression (2x + 6y)³ expands to 8x³ + 72x²y + 216xy² + 216y³.