A coin math problem, urgent!

Let 1 angle (0. 1 yuan), angle 5 (0.5 yuan) and 1 yuan each take x, y, z, y, z, then

x+y+z= 15( 1)

0. 1x+0.5y+z=7(2)

x= 15-y-z

x+5y+ 10z=70

15-y-z+5y+ 10z=70

4y+9z=55(3)

9z & lt=55

So z < =6 (and z & gt=0, z is an integer).

So z can only take some values of 0, 1, 2, 3, 4, 5 and 6.

Verify one by one: Substitute (3)

When z=0, 1, 2, 4, 5, 6, y is the score, not the meaning of the topic.

When z=3, y = 7 and x = 5 (x = 5 is to substitute the first two values (1)).

So 1 angle is 5, 5 angle is 7, and 1 element is 3.