Answer: 40
Step-by-step explanation:
Number of correct questions Sally got = 28 questions
Percentage of correct questions answered= 70% on the exam,
Total number of questions in the exam = Unknown
Let the total questions in the exam be represented as y.
Since Sally got 70% correctly, this will be:
70% of y = 28
70/100 × y = 28
0.7 × y = 28
0.7y = 28
Divide both side by 0.7
0.7y/0.7 = 28/0.7
y = 40
There are 40 questions in the exam.
6a+8b; when a variable is next to a coefficient then that means they are multiplying each other, we just don't know what a or b is.
Answer:
x = ±25
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
<u>Algebra I</u>
Step-by-step explanation:
<u>Step 1: Define</u>
x² = 625
<u>Step 2: Solve for </u><em><u>x</u></em>
- Square root both sides: x = ±25
<u>Step 3: Check</u>
<em>Plug in x into the original equation to verify it's a solution.</em>
x = -25
- Substitute in <em>x</em>: (-25)² = 625
- Exponents: 625 = 625
Here we see that 625 does indeed equal 625.
∴ x = -25 is a solution to the equation.
x = 25
- Substitute in <em>x</em>: 25² = 625
- Exponents: 625 = 625
Here we see that 625 does indeed equal 625.
∴ x = 25 is a solution to the equation.
Answer:
No this is a not good experimental design
Step-by-step explanation:
In an experiment, we seek to establish cause an effect relationship. The effect of one variable on another is examined while keeping other variables constant. A control often establishes the validity of the experiment.
Now the ten rubber bands were selected at random from each box. The experimental group was put in a freezer while the control group was maintained at room temperature.
Comparison of the mean stretch before breakage of the rubber bands in both groups establishes the effect of cold temperature on elasticity of rubber bands.
However, this is not a good experimental design because the sample rubber bands should have been picked from different boxes of brand A and B and not from the same box.
Secondly, samples from the two brands should have been put in the freezer and kept at room temperature. That is, ten rubber bands from A are put on the freezer and another 10 are left at room temperature. 10 rubber bands from B are put in the freezer and another 10 are left at room temperature.
The mean elasticity of the both groups can now be meaningfully compared from the data obtained.
