Answer: 0.067 litres of water
Step-by-step explanation:
The mode is:
Concentration of new solution = Moles of acid in original solution / (Volume of original solution + Volume of water added)
Assume volume of water added is w.
12 = 16 (0.2) / (0.2 + w)
(0.2 + w) * 12 = 3.2
0.2 + w = 3.2 / 12
w = (3.2 / 12) - 0.2
w = 0.067 litres of water
Step-by-step explanation:
Pythagoras (for right-angled triangles) :
c² = a² + b²
c being the Hypotenuse, the side opposite of the right angle. and that would be here the diagonal.
c = diagonal = 10 ft
therefore, the width of the rectangle is 10/2 = 5 ft
10² = 5² + b²
100 = 25 + b²
b² = 75
b = length = sqrt(75) = 8.660254038... ft
Answer:
x = - 7, x = 
Step-by-step explanation:
Given
2x² + 13x - 7 = 0
Consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term.
product = 2 × - 7 = - 14 and sum = + 13
The factors are + 14 and - 1
Use these factors to split the x- term
2x² + 14x - x - 7 = 0 ( factor the first/second and third/fourth terms )
2x(x + 7) - 1(x + 7) = 0 ← factor out (x + 7) from each term
(x + 7)(2x - 1) = 0
Equate each factor to zero and solve for x
x + 7 = 0 ⇒ x = - 7
2x - 1 = 0 ⇒ 2x = 1 ⇒ x = 