Lets call x the amount of 18% solution and y the amount of 40% solution, and write as equations the info of the problem:
18x + 40y = 10(20)
x + y = 10
lets multiply the second equation by -18 and add to the first:
18x + 40y = 200
-18x -<span> 18y = -180
</span>----------------------
0 + 22y = 20
y = 20/22 = 10/11
and substitute in the original equation:
x <span>+ y = 10
</span>x = 10 - y
x = 10 - 10/11
x = 110/11 - 10/11
x = 100/11
so they have to use 100/11 liters of 18% solution and 10/11 liters of 40% solution
Answer:
5. -2 3/4, -2.2, 2.8, 3 1/8
6. -0.6 , 0.65 , 2/3 , 4/5
Step-by-step explanation:
Answer:
150m by 300 m
Step-by-step explanation:
150×300=45000
all sides add up to 900m
150+150+300+300
Answer:5.5%
Step-by-step explanation:
just use it smh