percent math question

Question

solution 1 contains 7.00% sugar and solution 2 contains 4.00% sugar.

how much of sugar solution 1 and 2 do you have to mix in order to get 35.0kg of sugar solution that contains 6.00% sugar

Answer 1

7x +4(35-x)= 6(35)

7x -4x = 6(35)- 4(35)= 2(35)=70

3x = 70

x=70/3 = 23 1/3 kg of 1st solution

35-x = 11 2/3 kg of 2nd

7-6=1

6-4=2= twice as much 7 as 4% needed

2/1= 23 1/3/11 2/3

7(70)/3+4(35/3

=490/3 +140/3

=630/3

=210

=2.1 kg sugar

6(35)

=210

=2.1 kg sugar