Tolong kerjain yaaaaaa
2 ) -3 + [7+(-1×3)] + 7 – 20
= -3 + 4 + 7 – 20
= 8 – 20
= -12 (a)
3 ) 2x – 5 = 7
2x = 7 + 5
2x = 12
x = 6 (b)
4 ) 4x + 2 = x – 4
4x – x = -4 – 2
3x = -6
x = -2 (d)
5 ) 3x + 2 = x – 4
3x – x = -4 – 2
2x = -6
x = -3 (c)
6 ) 7 – x – x²
= 7 – (-2) – (-2)²
= 7 + 2 + 4
= 13 (d)
7 ) 2 – x³
= 2 – (-2)³
= 2 + 8
= 10 (b)
8 ) c
9 ) a
12 ) 5 + px = -7
5 + p.-3 = -7
5 – 3p = -7
-3p = -7 – 5
-3p = -12
p = 4 (d)
13 ) ayah + ibu + anak = 123 tahun
ibu = 48 tahun
ayah + anak = 75 tahun
75 = 2 anak + anak
75 = 3 anak
25 = 1 anak (c)
15 ) 28 x 3/7 = 12 (b)
16 ) x² = 16
x = √16
x = 4(b)