How do I solve this?

Question

A company needs 1450 kg of a solution that is 15% ethanol and 85% water. The company has a 5% ethanol solution (remainder is water) and a 30% ethanol solution (remainder is water) in stock. How many kg of each of these solutions should be mixed together?

Answer 1

.05x +.3(1450-x)=.15(1450)

(.05-.3)x = (.15-.3)(1450

.25x= .15(1450)

x= .15(1450)/.25

x=(3/5)(1450)

x=3(290)

x= 870 kg 5%

580 kg 30%

.3(580)+.05(870)

= .05(6(580 +870)

=.05(3480+870)

=.05(4350)

= 217.5

=.15(1450)

=217.5

30-15=15

15-5=10

15/10=1.5

x/(1450-x)=3/2

2x=4350-3x

5x=4350

x=870 kg 5%

1450-870=580 kg 30%