Ask for help to solve an applied problem of linear equations with 2 variables (set two different unknowns) The distance between a and B is 42km. If two people are walking opposite each other at the same time, they will meet in two hours. If B starts in the opposite direction, a will catch up immediately and use 14 to disappear to catch up, so as to find the speed of a and B

Ask for help to solve an applied problem of linear equations with 2 variables (set two different unknowns) The distance between a and B is 42km. If two people are walking opposite each other at the same time, they will meet in two hours. If B starts in the opposite direction, a will catch up immediately and use 14 to disappear to catch up, so as to find the speed of a and B

Let the velocities of a and B be x and Y respectively. The following equations can be formulated: 2 (x + y) = 42; 14 (X-Y) = 42
The simultaneous equations are: x = 12; y = 9

Use equation to solve practical problems, and use () to express unknowns; use arithmetic to solve practical problems, and use () to express unknowns
emergency

To solve practical problems with equations, the unknowns are expressed with (letters); to solve practical problems with arithmetic, the unknowns are (not in) the expressions

If the equations {x + y = 3, X-my = 2} and {X-Y = 1, nx-y = 2} have the same solution, find the value of M, n

Because we have the same solution
So first, x + y = 3 and X-Y = 1 form the equations
X+Y=3 (1)
X-Y=1 (2)
(1) + (2) get: 2x = 4
X=2
Then y = 3-x = 1
When x and y are brought into X-my = 2 and nx-1 = 2, the following results are obtained:
2-M=2
2N-1=2
Then M = 0, n = 3 / 2