Find the value of: [4 MARKS]

(i) $p + q + 3 r$
$w h e n p = 1, q = 5, r = 2$

(ii) $2 a + 4 b + 5 c$
$w h e n a = 5, b = 10, c = 20$

(iii) $3 a - 2 b$
$w h e n a = 8, b = 10$

(iv) $5 x + 3 y - 6 z$ ,
$w h e n x = 3, y = 5, z = 4$

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Solution

Each option: 1 Mark

(i) $p + q + 3 r, w h e n p = 1, q = 5, r = 2$

$p + q + 3 r = 1 + 5 + 3 (2) = 12$

(ii) $2 a + 4 b + 5 c, w h e n a = 5, b = 10, c = 20$

$2 a + 4 b + 5 c = 2 (5) + 4 (10) + 5 (20)$

$= 10 + 40 + 100 = 150$

(iii) $3 a - 2 b, w h e n a = 8, b = 10$

$3 a - 2 b = 3 (8) - 2 (10)$

$= 24 - 20 = 4$

(iv) $5 x + 3 y - 6 z, w h e n x = 3, y = 5, z = 4$

$5 x + 3 y - 6 z = 5 (3) + 3 (5) - 6 (4) = 15 + 15 - 24$

$= 30 - 24 = 6$

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Find the value of: [4 MARKS] (i) p+q+3r when p=1,q=5,r=2 (ii) 2a+4b+5c when a=5,b=10,c=20 (iii) 3a−2b when a=8,b=10 (iv) 5x+3y−6z, when x=3,y=5,z=4

Each option: 1 Mark (i) p+q+3r,when p=1,q=5,r=2 p+q+3r=1+5+3(2)=12 (ii) 2a+4b+5c, when a=5,b=10,c=20 2a+4b+5c=2(5)+4(10)+5(20) =10+40+100=150 (iii) 3a−2b, when a=8,b=10 3a−2b=3(8)−2(10) =24−20=4 (iv) 5x+3y−6z, when x=3,y=5,z=4 5x+3y−6z=5(3)+3(5)−6(4)=15+15−24 =30−24=6

Find the value of: [4 MARKS]

(i) $p + q + 3 r$
$w h e n p = 1, q = 5, r = 2$

(ii) $2 a + 4 b + 5 c$
$w h e n a = 5, b = 10, c = 20$

(iii) $3 a - 2 b$
$w h e n a = 8, b = 10$

(iv) $5 x + 3 y - 6 z$ ,
$w h e n x = 3, y = 5, z = 4$