tolong nomor 29 & 30

29.
Keliling = 2(p + l)
32 = 2(3a + 3 + 2a - 2)
32 = 2(5a + 1)
32 = 10a + 2
32 - 2 = 10a
30 = 10a
30 : 10 = a
a = 3

p = 3a + 3
= 3(3) + 3
= 9 + 3
= 12 cm

l = 2a - 2
= 2(3) - 2
= 6 - 2
= 4 cm

Luas = p × l
= 12 × 4
= 48 cm^2 (C)

30.
[tex]a = 2 {x}^{2} + 3 \\ b = 1 - {x}^{2} [/tex]
[tex]2a + 3b \\ = 2(2 {x}^{2} + 3) + 3(1 - {x}^{2} ) \\ = 4 {x}^{2} + 6 + 3 - 3 {x}^{2} \\ = (4 {x}^{2} - 3 {x}^{2} ) + (6 + 3) \\ = {x}^{2} + 9[/tex]
jawaban = B