tolong jawab..... Terima kasih

Mapel : Matematika
Kelas : VII SMP
Bab : Akjabar

Pembahasan :
(x + 9)²
→ (x + 9)(x + 9)
→ x.x + x.9 + 9.x + 9.9
→ x² + 9x + 9x + 81
→ x² + 18x + 81

(x + 4)²
→ (x + 4)(x + 4)
→ x.x + x.4 + 4.x + 4.4
→ x² + 4x + 4x + 16
→ x² + 8x + 16

(5x - 7)²
→ (5x - 7)(5x - 7)
→ 5x.5x - 5x.7 - 7.5x -7.-7
→ 25x² - 35x - 35x + 49
→ 25x² - 70x + 49

(6x + 3y)²
→ (6x + 3y)(6x + 3y)
→ 6x.6x + 6x.3y + 3y.6x + 3y.3y
→ 36x² + 18xy + 18xy + 9y²
→ 36x² + 36xy + 9y²

a. (x+9)²
= (x+9)(x+9)
= x²+9x+9x+81
= x²+18x+81

b. (x+4)²
= (x+4)(x+4)
= x²+4x+4x+16
= x²+8x+16

c. (5x-7)²
= (5x-7)(5x-7)
= 25x²-35x-35x+49
= 25x²-70x+49

d. (6x+3y)²
= (6x+3y)(6x+3y)
= 36x²+18xy+18xy+9y²
= 36x²+36xy+9y²