Question

kuis.y ...............​

Answer 1

A.) Nilai a

(3a + 4)² = (3a + 2)² + (a + 4)²

(3a + 4)(3a + 4) = (3a + 2)(3a + 2) + (a + 4)(a + 4)

9a² + 24a + 16 = 9a² + 12a + 4 + a² + 8a + 16

9a² - 9a² - a² + 24a - 12a - 8a + 16 - 4 - 16 = 0

-a² + 4a - 4 = 0

(a - 2)(-a + 2) = 0

a = 2

B.) Keliling segitiga

= 3a + 4 + 3a + 2 + a + 4

= 7a + 10

= 7(2) + 10

= 14 + 10

= 24 satuan

C.) Luas segitiga

= alas × tinggi

= (a + 4) × (3a + 2) ÷ 2

= (2 + 4) × (3(2) + 2) ÷ 2

= 6 × 8 ÷ 2

= 48 ÷ 2

= 24 satuan luas

Answer 2

Jawab:

A. a= 4

B. 38

C. 56

Penjelasan dengan langkah-langkah:

A. 3a+4 = (3a+2)²+(a+4)²

3a+4 = 3a²+4+a²+16

3a+4 = 4a²+20

4a²-3a = 20-4

(4a-3a)a = 16

a²= 16,  a= √16

a=4

B. - 3a+2 = 3*4+2= 12+2= 14

- a+4= 4+4= 8

- 3a+4= 3*4+4= 12+4= 16

Keliling= 14+8+16= 38

C. Luas = 1/2 * a * t

1/2 * 8 * 14 = 56