Question

WHHAT IS 3x(4x-5)+3 IF x =1/2 answer with explanation

Answer 1

Answer:

given

Step-by-step explanation:

3x (4x – 5) + 3

3x (4x – 5) + 3 = (3x × 4x) – (3x × 5) + 3

3x (4x – 5) + 3 = 12x2 – 15x + 3

Substitute the value of (i) x = 3 in 12x2 – 15x + 3

12x2 – 15x + 3

Put x = 3

⇒ 12 × (32) – (15 × 3) + 3

⇒ 12 × 9 – 45 + 3

⇒ 108 – 45 + 3

⇒ 66

Substitute the value of (ii) x =1/2 in 12x2 – 15x + 3

12x2 – 15x + 3

Put = 1/2

⇒ 12 × (1/2)2 – (15 × 1/2) + 3

⇒ 12 × 1/4 – (15 × 1/2) + 3

⇒ 3 – 15/2 + 3

⇒ 6 – 15/2

⇒ (12 – 15)/2

⇒ -3/2

Answer 2

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Question -

$3x(4x - 5) + 3$

If

$x = \frac{1}{2}$

$3x(4x - 5) + 3 \\ = 3 \times \frac{1}{2} (4 \times \frac{1}{2} - 5) + 3 \\ = 3 \times \frac{1}{2} \times ( - 3) + 3 \\ = \frac{3}{2} \times ( - 3) + 3 \\ = \frac{ - 9}{2} + 3 \\ = \frac{ (- 9) + 6}{2} \\ = \frac{ - 3}{2}$