tolong jawab 2 nomor ini
Jawaban:
1. D
2. D
Penjelasan dengan langkah-langkah:
1.
K= 40 cm
4 × s= 40 cm
s= 10 cm
s²= (1/2d1)²+(1/2d2)²
s²= (1/2 × 12 cm)²+(1/2× d2)²
(10 cm)²= (6 cm)²+(1/2 × d2)²
64 cm²= (1/2 × d2)²
8 cm= 1/2 × d2
d2= 16 cm
Luas= d1 × d2/2
= 12 cm × 16 cm/2
= 12 cm × 8 cm
= 96 cm²
V=1/3 × 96 cm² × 15 cm
= 32 cm² × 15 cm
= 480 cm³
2.
f(2)= 4
2a+b= 4
f(5)= 13
5a+b= 13
------------ -
-3a= -9
a= 3
2a+b= 4
2(3)+b= 4
b= -2
f(x)= 3x-2
f(3)= 3(3)-2
= 9-2
= 7
Penjelasan dengan langkah-langkah:
1. D. 480 cm³
Keliling alas = 4s
s = 40/4
s = 10 cm
d1 = 12 cm
d2 = 2 x √(10² - [12/2]²)
d2 = 2 x √(100-36)
d2 = 2 x √64
d2 = 2 x 8
d2 = 16 cm
t = 15 cm
t/3 = 15/3 = 5 cm
Volume = d1 x d2 x t/3
2
Volume = 12 x 16 x 5
2
Volume = 192 x 5
2
Volume = 96 x 5
Volume = 480 cm³
2. D. 7
f(x) = ax + b
f(2) = 2a + b = 4
f(5) = 5a + b = 13 –
–3a = –9
a = –9/–3
a = 3
2a + b = 4
2(3) + b = 4
6 + b = 4
b = 4 – 6
b = –2
f(x) = 3x –2
f(3) = 3(3) – 2
f(3) = 9 – 2
