How to solve the equation of 16.2 + 4x = 8x?

16.2=8x-4x
16.2=4x
x=4.05

The original price of a certain commodity is 200 yuan. When it is sold, the price will be reduced by 10% for the first time and 10% for the second time. How much is the price after two price reductions?
And explain why

200*0.9*0.9

Solution equation: (4 + x) × (2 + x) - x × x = 44

8+6X+X×X-X×X=44
6X=36
X=6

The price of a commodity is reduced by 30% the first time and 20% the second time

The price of a commodity is reduced by 30% for the first time and 20% for the second time, which is 1 - (1-30%) × (1-20%) = 44% lower than the original price

2 × (x + 1) = 16

2×(x+1)=16
2x+2=16
2x=16-2
2x=14
x=7

The price of a commodity is reduced by 20% for the first time and then increased by 20%. The current price is () of the price before the reduction
A. 96 percent
B. 100 percent
C. 80 percent
2. If the denominator of two fifths is added with 5, in order to keep the size of the fraction unchanged, the numerator should be ()
A.10
B.7
C.4
D.2
3. If a cylinder and a cone are equal in height and base, and the volume of the cylinder is 8 cubic centimeters more than that of the cone, then the volume of the cone is ()
A. 16 CC
B. 12 CC
C. 8 cc
D. 4 cm3

ACD

(1) The sum of a number and one twelfth is equal to 15% of two-thirds of the total. What is this number? (2) 62.5% of a number plus 8, and
(3) if 30% of a number is 150, how much is 50% of the number. (4) what is the product of 25% of 120 divided by two-thirds and three-quarters?

Let this number be X
x+1/12=2/3×15%
x+1/12=1/10
x=1/60
Let this number be X
62.5%x+8=3x/4
0.125x=8
x=64
150÷30%× 50%
=500× 50%
=250
120× 25%÷（1/2×3/4）
=30÷3/8
=80
May I help you!

Solve the equation x + 2.6 = 16

x+2.6=16
x=16-2.6
=13.4

The price of a commodity will be reduced by 20% first and then increased by 20%. How much is the current price before the reduction?

Let the original price be x, after the price reduction be (1-0.2) x, after the price increase be (1 + 0.2) (1-0.2) x = (1-0.04) x = 0.96x, which is 96% of the original price

It is known that a = (11 × 66 + 12 × 67 +) +15×70/11×65+12×66+… +15×69）×100 a=?

a=(11×66+12×67+13×68+14×69+15×70)/(11×65+12×66+13×67+14×68+15×69)
B = 100A, then the integral part of B is?
Answer 101

How to solve the equation of 16.2 + 4x = 8x?