Solving the system of inequalities 0.3x + 0.1 (150-x) ≤ 10.2.0.1x + 0.1 (150-x) ≤ 10.2

Solving the system of inequalities 0.3x + 0.1 (150-x) ≤ 10.2.0.1x + 0.1 (150-x) ≤ 10.2

If both sides of the inequality multiply by 10, 0.3x + 0.1 (150-x) ≤ 10.2 becomes 3x + 150 - ≤ 102, X ≤ - 24
Similarly, if 0.1 x + 0.1 (150-x) ≤ 10.2, X is all real numbers,
So x ≤ - 24

How to do 3 + 2 / 1 x = 4x and 3x-2 (5x-4) = 2 + (5-6) x

(1) 3+x/2=4x
Multiply both sides by 2 to get 6 + x = 8x
7x=6
x=6/7
(2) Is that line a minus sign? It's 3x-2 (5x-4) = 2 + (5-6) X

Make up a practical problem, make the equation 3x + 4 (45 - x) = 150, and communicate with students

A. B is 150 km apart. The sum of the speed of a and B is 45 km / h. one hour after a starts from a, B starts from B, and three hours later they meet. How many kilometers does B walk per hour?

According to your life experience, please write a practical problem to make the equation 3x + 4 (x + 6) = 120

Party A and Party B travel from a and B, which are 120km apart. It is known that the speed of Party A is 3km / h, and that of Party B is 4km / h. Moreover, they set out 6 hours earlier. How many hours can they meet?