Respuesta :
2b + 5j = 6.35.....multiply by -2
4b + 12j = 13.20
----------------------
-4b - 10j = - 12.70 (result of multiplying by -2)
4b + 12j = 13.20
----------------------add
2j = 0.50
j = 0.50/2
j = 0.25 <==== jars
2b + 5j = 6.35
2b + 5(0.25) = 6.35
2b + 1.25 = 6.35
2b = 6.35 - 1.25
2b = 5.10
b = 5.10/2
b = 2.55 <=== brushes
so 1 brush (b) = 2.55 and 1 jar (j) = 0.25...total, if needed, = 2.80
4b + 12j = 13.20
----------------------
-4b - 10j = - 12.70 (result of multiplying by -2)
4b + 12j = 13.20
----------------------add
2j = 0.50
j = 0.50/2
j = 0.25 <==== jars
2b + 5j = 6.35
2b + 5(0.25) = 6.35
2b + 1.25 = 6.35
2b = 6.35 - 1.25
2b = 5.10
b = 5.10/2
b = 2.55 <=== brushes
so 1 brush (b) = 2.55 and 1 jar (j) = 0.25...total, if needed, = 2.80