a. (6a+6b)² b. (4ײ-7y²)² c. 5(-2ײ-9×) ² Tolong jawab lg yh ka

a (6a + 6b)²
= (6a + 6b)(6a + 6b)
= 6a(6a + 6b) + 6b(6a + 6b)
= 36a² + 36ab + 36ab + 36b²
= 36a² + 72ab + 36b
b (4x² - 7y²)²
= (4x² - 7y²)(4x² - 7y²)
= 4x²(4x² - 7y²) + 7y²(4x² - 7y²)
= 16x⁴ - 28x²y + 28x²y² - 49y⁴
= 16x⁴ - 49y⁴
c 5(-2x² -9x)²
= 5(-2x² - 9x)(-2x² - 9x)
= 5 - 2x²(-2x² - 9x) + 9x(-2x² - 9x)
= 5 + 4x⁴ + 18x³ - 18x³ - 81x²
= 5 + 4x² - 81x²