First student bought art, math and history books for $72. second student bought art, chemistry and history books for $80. third student bought chemistry, math and history books for $61. fourth student bought art, math and chemistry books for $57. how much does each book cost?

A + M + H = $72
A + C + H = $80
C + M + H = $61
A + M + C = $57

Difference between first student and second student = Math VS Chemistry
80 - 72 = 8
Therefore Chemistry = Math + $8
And Math = Chemistry - 8

Difference between second and third student = Art VS Math
80 - 61 = 19
Therefore Art = Math + 19
And Math = Art - 19

If C = M + 8 and A = M + 19
Then Art = Chemistry + 11
And Chemistry = Art - 11

Difference between third and fourth student = History VS Art
61 - 57 = 4
Therefore History = Art + 4
And Art = History - 4

Using trial and error, if A = 29
A + M + H = 72
29 + M + H = 72
29 + 10 + 33 = 71
Therefore,
Art = $29
Math = $10
History = $33

C = M + 8
C = 10 + 8
C = 19
So Chemistry = $19

On the horizontal axis

Step-by-step explanation:

The complex number is represented by the complex plane or z-plane which is the representation geometrically of the real (number) axis and the imaginary (number) axis

When plotting complex numbers, the real part of the complex number is always plotted on the horizontal axis while the imaginary part is plotted on the vertical axis

The complex plane concept facilitates the description of complex numbers geometrically.