Solution equation: 1.5x + 0.4 * 13 = 10

1.5x+0.4*13=10
1.5x+5.2=10
1.5x=4.8
x=3.2

Solve the equation. 1: 5x-8.7 = 10.92 2: 2.1 × 7 + 1.5x = 23.7
3 questions 0.8x + 3.2X = 10
4 questions (x + 5) × 1.3 = 16.9
A series of equations. The solution of the equation is obtained.
(1) The number eight less than three times a number is 15. What's the number?
(2) Eight times the number is more than five times the number. 72. What's the number?
(1) Lily bought eight exercise books, paid 10 yuan, and recovered 0.4 yuan. How much is each exercise book?
(2) Build a section of road, 4.8 kilometers per day. 5 days, if 6 meters a day, how many days?
(3) A and B trains leave 490 km apart at the same time. After 2.8 hours, a train runs 95 km per hour, and B train runs how many km per hour?
(4) There are 6500 science and technology books in the library of the school. The number of science and technology books is more than 100 than that of storybooks. How many storybooks are there?
(5) The number of panda dolls produced by the toy factory in a week is 360 more than that of monkey dolls. If the number of bear dolls is five times that of monkey dolls, how many dolls will be produced after verification?

Question 1: 5x-8.7 = 10.92
5x=10.92+8.7
5x=19.62
x=3.924
Question 2: 2.1 × 7 + 1.5x = 23.7
14.7+1.5x=23.7
1.5x=23.7-14.7
1.5x=9
x=6