Question 1025047
b+r = 48 (1)
b = 2r-12 Use this value for b in equation (1):
2r-12+r = 48 add 12 on both sides and add r on left:
3r = 60 
r = 20 There are 20 red notebooks and the problem says:
b = 2r-12 = 2(20)-12=40-12= 28 There are 28 blue notebooks