Page 55 - Hybrid PBD 2021 Form 2 - Matematik

Matematik Tingkatan 2 Bab 3
4. Ungkapkan pemboleh ubah dalam kurungan sebagai perkara rumus. SP 3.1.2 TP3
Express the variable in the brackets as the subject of the formula.

1
1
(i) p = 4x + 7 [x] (ii) 1 + = [g]
a 3 g
Kumpulkan perkara rumus yang
p = 4x + 7 dikehendaki pada sebelah kiri. 1 + = 1
1
4x + 7 = p Group the desired subject of formula on the left. a 3 g
1
4x + 7 – 7 = p – 7 Samakan pekali. 1 = + 1
4x ÷ 4 = (p – 7) ÷ 4 Equalise the denominators. g a 3
p – 7 1 3 + a
x = =
4 Lakukan pendaraban silang. g 3a
Perform the cross-multiplication.
g(3 + a) = 3a
Lakukan konsep kesamaan. 1 1
Perform the equality concept. g(3 + a) × = 3a ×
3 + a 3 + a
3a
g =
3 + a
2
(a) h = 8p + 7 [p] (b) x = z + 2y [y] (c) 3x = y – z [z]
2
2
8p + 7 = h x = z + 2y
2
2
8p + 7 – 7 = h – 7 z + 2y = x 2 y – z = 3x
2
2
8p = h – 7 z – z + 2y = x – z 2 y – – z = 3x – y
2
2
y
2
8p ÷ 8 = (h – 7) ÷ 8 2y ÷ 2 = (x – z ) ÷ 2 2 2 2
2
2
h – 7 x – z 2 1 1 y 2 1
2
p = y = –z × –1 = 3x – × –1
8 2 2
y
z = – 3x
2

4 – 3w 2(y – 2) (f) 9k = 3(5g – h) [h]
(d) J = [w] (e) = y [y]
w 3p
4 – 3w 2(y – 2) 3(5g – h) = 9k
J = = y
1
w 3p 3(5g – h) × = 9k × 1
4 – 3w 3 3
J × w = × w 2(y – 2) × 3p = y × 3p
w 3p 5g – h = 3k
Jw = 4 – 3w 2y – 4 – 3py + 4 = 3py – 3py + 4 5g – h – 5g = 3k – 5g
Jw + 3w = 4 – 3w + 3w 2y – 3py = 4 –h = 3k – 5g
Jw + 3w = 4 1 1
w(J + 3) = 4 y(2 – 3p) = 4 –h × –1 = (3k – 5g) × –1
1 1 y(2 – 3p) × 1 = 4 × 1
w(J + 3) × = 4 × 2 – 3p 2 – 3p h = –3k + 5g
J + 3 J + 3
4 y = 4
w = 2 – 3p
J + 3

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Bab 3.indd 28 9/3/21 5:13 PM