need help plz math

Question

Find how many quarts of

6​%

butterfat milk and

3​%

butterfat milk should be mixed to yield

30

quarts of

4​%

butterfat milk.

Answer 1

6x = (30-x)3 = 4(30 = 120

6x -3x = 120-3(30) = 120-90 = 30

3x = 30

x = 30/3 = 10 quarts of 6% mixed with 20 quarts of 3% gives 30 quarts of 4%

3 is closer to 4 than 6

3 is within 1 of 4

6 is within 2 of 4

2 is twice 1

you need twice as much 3% as 6%

20 quarts is twice 10 quarts

.06(10) + .03(20) = .6 +.6 = 1.2

.04(30) = 1.2