13.15 ounces of 72% acid and 71.85 ounces of 25% acid are needed
<u>Step-by-step explanation:</u>
Total mass of acid required= 85 ounces
Let the mass of 72% acid be 'a'
Let the mass of 25% acid be 'b'
a + b = 85
b = 85-a
85(40/100) = a(72/100) + b(25/100)
85(2/5) = a(72/100) +(85- a) (25/100)
34 = (72a/100) + (2125/100) - (25a/100)
34 - (2125/100) = (72a + 25a) /100
(3400-2125)/100 = 97a /100
97a = 1275
a = 13.15 ounces
b = 85 - 13.14
b = 71.85 ounces
13.15 ounces of 72% acid and 71.85 ounces of 25% acid are needed
Let's go through this problem step by step while bearing in mind the concept of
PEMDAS.
Step 1:

Declaration of the expression. Nothing wrong here yet.
Step 2:

Clarise evaluated what's inside the parenthesis first - which was the right thing to do! There are no mistakes in this step.
Step 3:

In this step she subtracted first. This should not be the case! PEMDAS tells us that the exponents and division gets higher priority than subtraction. This is therefore the first mistake Clarise makes.
Step 4:

In this step Clarise evaluates the exponent. This does not violate any rules (relative to the previous expression) since PEMDAS tells us that exponents take higher priority than division.
Step 5:

(Clarise's final answer)
In Clarise's final step, she manages to get the wrong answer! Dividing 51.68 by 0.16 would give us 323. This is another mistake of Clarise.
Looking at the choices, we can now identify what mistakes Clarise made:
-She subtracted before evaluating the exponents
-She subtracted before she divided
-She divided incorrectly
3/5 = .6 and 4/10 = .4, so 3/5 is greater than 4/10
Answer:
Complete the following statements.
The functions f and g have the same axis of symmetry.
The y-intercept of f is greater than the y-intercept of g.
Over the interval [-6, -3], the average rate of change of f is less than the average rate of change of g.
ANSWER
Option B
and
Option D.
EXPLANATION
The graph of the function has an amplitude of 2 and a period of

Choose all the equation that has an amplitude of 2 and a period of

These are:

and

The second and the last options are correct.