Math problems in Volume 1 of Grade 8 - if 2N-1 power of 3 + n power of 9 = 108, find the n power of (2n-2)

Math problems in Volume 1 of Grade 8 - if 2N-1 power of 3 + n power of 9 = 108, find the n power of (2n-2)

2N-1 power of 3 + n power of 9 = 108
2n power of 3 + 3 × 2n power of 3 = 324
2n power of 3 = 81
2n power of 3 = fourth power of 3
∴2n=4
n=2
(2n-2) to the nth power = (4-2) ²= four

: calculate (1-1 / 2 to the second power) (1-1 / 3 to the third power)... (1-1 / 9 to the ninth power) (1-1 / 10 to the tenth power)

Square difference
=(1-1/2)(1+1/2)(1-1/3)(1+1/3)……(1-1/10)(1+1/10)
=(1/2)(3/2)(2/3)(4/3)……(9/10)(11/10)
Middle divisor
=(1/2)(11/10)
=11/20

(1) Given the 55th power of a = 3, the 44th power of B = 4 and the 33rd power of C = 5, try to compare the sizes of a, B and C You'd better write out the detailed solution

a=3^55=3^(5 × 11)=(3^5)^11=243^11
b=4^44=4^(4 × 11)=(4^4)^11=256^11
c=5^33=5^(3 × 11)=(5^3)^11=125^11
256＞243＞125
256^11＞243^11＞125^11
b＞a＞c

What is the speed of sound in the air

Velocity of sound (sonic speed) is also called sound speed. Sound speed is the propagation speed of weak pressure disturbance in the medium, and its size varies according to the nature and state of the medium. The sound speed in the air is about 340m / s at 1 standard atmospheric pressure and 15 ℃

How fast does sound travel through the air

Velocity of sound (sonic speed) is also called sound speed. Sound speed is the propagation speed of weak pressure disturbance in the medium, and its size varies according to the nature and state of the medium. The sound speed in the air is about 340m / s at 1 standard atmospheric pressure and 15 ℃

The propagation speed of sound at 15 ℃ in air is () m / s, which is faster and slower in water than in air ()

About 340 m / s, faster in liquid than in gas, so faster in water