Let x = the number of chemistry textbooks.
x + 2x = 315
3x = 315
x = 105
A textbook store sold a combined total of 315 physics and chemistry textbooks in a week. The number of physics textbooks sold was two times the number of chemistry textbooks sold. How many textbooks of each type were sold?
3 answers
p + c = 315
p =2c
Replace p with the 2c in the first equation.
2c + c = 315
solve for "c"
then you can find p.
p =2c
Replace p with the 2c in the first equation.
2c + c = 315
solve for "c"
then you can find p.
Y=105
X=210
X=210