Please hejp A 40% antifreeze solution is to be mixed with a 70% antifreeze solution to get 240 liters of a 58% solution. How many liters of the 40% and how many liters of the 70% solutions will be used?

part 1:

see in the picture, E is the centre of the kite

1) AC = 2.EC = 40

2) CD = sqrt( ED² + EC² ) = sqrt(21² + 20²) = 29

3) ABE = 90⁰ - 51⁰ = 39⁰

4) BCE = BAE = 51⁰

part 2:

we have:

3x + 7 = (3x - 1 + 8x)/ 2

<=> 3x + 7 = 5.5x - 0.5

<=> 2.5x = 7.5

<=> x = 3

5) with x = 3 => UV = 3.3 - 1 = 9 - 1 = 8

6) XY = 3.3 + 7 = 9 + 7 = 16

7) TW = 8.3 = 24

9) the width of the base is x (x > 0)

we have:

28.5 = (x + 25)/2

<=> x + 25 = 57

<=> x = 32