If, $2^{x+y-2z}=8^{8z-5-y};5^{4y-6z}=25^{y+z};3^{4x-3z}=9^{x+z}$ then the value of $2x + 3y +5z$ is :
Answer & explanation
Correct answer: option 2
$2^{x+y-2z}=8^{8z-5-y};5^{4y-6z}=25^{y+z};3^{4x-3z}=9^{x+z}$ then the value of $2x + 3y +5z$
We know that,
ap × aq = a{p + q}
2x+y-2z = 88z-5-y
= 2x+y-2z = 23(8z-5-y)
Comparing on power
= x + y - 2z = 24z - 15 - 3y
= x + 4y - 26z = -15 ----(A)
54y-6z = 25y+z
= 54y - 6z = 52 (y + z)
Comparing on power
= 4y - 6z = 2 (y + z)
= 4y - 6z = 2y + 2z
= 2y = 8z
= y = 4z ----(B)
34x-3z = 9x+z
= 34x-3z = 32(x + z)
Comparing on power
= 4x - 3z = 2x + 2z
= 4x - 2x = 2z + 3z
= 2x = 5z
= x = 2.5z ----(C)
From equation (A), equation (B) and equation (C)
= x + 4y - 26z = -15
= 2.5z + 4 (4z) - 26z = - 15
= 2.5z + 16z - 26z = - 15
= - 7.5z = - 15
= z = 2
From equation (B)
y = 4 × 2
= y = 8
From equation (C)
x = 2.5 × 2
= x = 5
Now,
2x + 3y + 5z
= 2 × 5 + 3 × 8 + 5 × 2
= 10 + 24 + 10 = 44