Alex purchased a history book and a math book for 100 Bob pu

Alex purchased a history book and a math book for $100. Bob purchased a history book, a math book, and a computer book for $150. Charly purchased a history book and a computer book for $80. If all of the history books were the same price, all of the math books were the same price, and all of the computer books were the same price, how much does each book cost?

Course: Linear Algebra_Matrices

Solution

Let price of history book be H, of math book be M and computer book be C

H+M=100

H+M+C=150

H+C=80

From first two equation

C=50

From third equation

H=30

From first equation

M=70