need help its been quit hard for me to solve this one

Question

A candy distributor needs to mix a 10% fat-content chocolate with a 30% fat-content chocolate to create 200 kilograms of a 24% fat-content chocolate. How many kilograms of each kind of chocolate must they use?

Answer 1

24-10=14

30-24= 6

14/6-7/3 times as much 30 as 10%

x/(200-x)=7/3

3x= 1400-7x

10x=1400

x=140 kg 30%

60 kg 10%

.3(140)+.1(60)=42+6=48

.24(200)= 48

.30x + .10(200-x) = .24(200)

.30x -.10x = .24(200) -.10(200)

.2x = .14(200)

x = (.14)(200)/.2 = 140 kg 30%

200-x = 60 kg 10%