Answer:
3 i think
Step-by-step explanation:
add 3 and 4 =7
or
multiply 2 and 3= 6 and subtract 3 = 3
x = liters of 5% solution
y = liters of 40% solution
The scientist wants 10 L total of a 20% solution, so
x + y = 10
0.05 x + 0.40 y = 0.20 (x + y) = 2
From the first equation,
y = 10 - x
Substitute this into the second equation and solve for x :
0.05 x + 0.40 (10 - x) = 2
0.05 x + 4 - 0.40 x = 2
2 = 0.35 x
x ≈ 5.714 L
Solve for y :
y = 10 - x
y ≈ 4.286 L
Answer:
l = 13 m
Step-by-step explanation:
Let's call the width of the rectangle x. Then we can form an expression for the length of the rectangle: 2x - 3
Now we need to form an equation for the area of the rectangle and solve it:
x(2x - 3) = 104
2x² - 3x = 104
2x² - 3x - 104 = 0 - now we need to factorize the equation
(2x + 13)(x - 8) = 0
Now we can say that x = 8 or x = -6.
Because we cannot have a negative length, x = 8 m.
Now we can workout the length using the expression that we formed at the beginning:
2x - 3 = l
2(8) - 3 = l
l = 16 - 3
l = 13 m