Answer:
1. (n + 3)(5n + 8)
2. (x - 4)(7x - 4)
3. (k + 8)(7k + 1)
Step-by-step explanation:
1. We have to factorize 5n² + 23n + 24.
Now, 5n² + 23n + 24
= 5n² + 15n + 8n + 24
= 5n (n + 3) + 8 (n + 3)
=(n + 3)(5n + 8) (Answer)
2. We have to factorize 7x² - 32x + 16
Now, 7x² - 32x + 16
= 7x² - 28x - 4x + 16
= 7x (x - 4) - 4 (x - 4)
= (x - 4)(7x - 4) (Answer)
3. We have to factorize 7k² + 57k + 8
Now, 7k² + 57k + 8
= 7k² + 56k + k + 8
= 7k (k + 8) + 1 (k + 8)
= (k + 8)(7k + 1) (Answer)
Let the three gp be a, ar and ar^2
a + ar + ar^2 = 21 => a(1 + r + r^2) = 21 . . . (1)
a^2 + a^2r^2 + a^2r^4 = 189 => a^2(1 + r^2 + r^4) = 189 . . . (2)
squaring (1) gives
a^2(1 + r + r^2)^2 = 441 . . . (3)
(3) ÷ (2) => (1 + r + r^2)^2 / (1 + r^2 + r^4) = 441/189 = 7/3
3(1 + r + r^2)^2 = 7(1 + r^2 + r^4)
3(r^4 + 2r^3 + 3r^2 + 2r + 1) = 7(1 + r^2 + r^4)
3r^4 + 6r^3 + 9r^2 + 6r + 3 = 7 + 7r^2 + 7r^4
4r^4 - 6r^3 - 2r^2 - 6r + 4 = 0
r = 1/2 or r = 2
From (1), a = 21/(1 + r + r^2)
When r = 2:
a = 21/(1 + 2 + 4) = 21/7 = 3
Therefore, the numbers are 3, 6 and 12.
Answer:
B
Step-by-step explanation:
Answer:
<h2>x = 5/2 , x = - 4/3</h2>
Step-by-step explanation:
6x² - 7x - 20 = 0
Using method of factorization
Rewrite - 7x as a difference
That's
6x² + 8x - 15x - 20 = 0
Factor the expression
That's
2x( 3x + 4) - 5( 3x + 4) = 0
Which is
(2x - 5) (3x + 4) = 0
2x - 5 = 0
2x = 5
Divide both sides by 2
x = 5/2
3x + 4 = 0
3x = - 4
Divide both sides by 3
x = -4/3
Hope this helps you
Answer:
b = 60? wha....
Step-by-step explanation:
