ISAT Examples #13-25

Multiply and combine like terms to determine the product of these polynomials.  $2x^2\left(4x-7xy+5\right)\left(3y-2\right)$  

•  $10x^3y^2-16x^3+30x^2y-20x^2$  

•  $-42x^3y^2+52x^3y^{ }-16x^3+30x^2y-20x^2$  

•  $10x^3y^2-36x^3+30x^2y$  

•  $-42x^6y^4+52x^6y^2-16x^6+30x^4y^2-20x^4$  

Michael took 12 tests in his math class. His lowest test score was 78. His highest test score was 98. On the 13th test, he earned a 64. Select whether the value of each statistic for his test scores increased, decreased, or could not be determined when the last test score was added.

• Increased: Standard Deviation

  Decreased: Mean

  Could Not Be Determined: Median

• Increased: Median

  Decreased: Standard Deviation

  Could Not Be Determined: Mean

• Increased: Mean

  Decreased: Median

  Could Not Be Determined: Standard Deviation

Determine whether each expression can be used to find the length of side RS. Select Yes or No for each expression.

• 35sin(R)

• 21tan(T)

• 35cos(R)

• 21tan(R)

The depth of a river changes after a heavy rainstorm. Its depth, in feet, is modeled as a function of time, in hours. Consider this graph of the function.

Enter the average rate of change for the depth of the river, measured as feet per hour, between hour 9 and hour 18. Round your answer to the nearest tenth.

Choose the domain for which each function is defined as $x\ne-4$  .

 

•  $f\left(x\right)=\frac{x+4}{x}$  

•  $f\left(x\right)=\frac{x}{x+4}$  

•  $f\left(x\right)=x\left(x+4\right)$  

•  $f\left(x\right)=\frac{4}{x^2+8x+16}$  

Consider this right triangle.

Enter the ratio equivalent to sin(B).

A train travels 250 miles at a constant speed (x), in miles per hour. Enter an equation that can be used to find the speed of the train, if the time to travel 250 miles is 5 hours. (no spaces).

A student solved $\frac{3}{x-4}=\frac{x}{7}$  in six steps, as show.
Step 1:  $3=\frac{x\left(x-4\right)}{7}$  

Step 2:   $21=x\left(x-4\right)$  

Step 3:  $21=x^2-4x$  

Step 4: $0=x^2-4x-21$  
Step 5:  $0=\left(x-7\right)\left(x+3\right)$  
Step 6:  $x=-3,\ x=7$  
Which statement is an accurate interpretation of the student’s work? 

•  The student solved the equation correctly. 

•  The student made an error in step 2. 

•  The student made an error in step 5. 

•  Only x = 7 is a solution to the original equation.

How many boxes would you click above the numbers to create a line plot for the given percent chances of rain in different cities.

65, 65, 70, 70, 80, 80, 80, 80, 85, 95, 95, 95, 100

How many above 65?

How many above 70?

How many above 80?

How many above 85?

How many above 95?

How many above 100?

Put answer in the form 65:_,70:_,80:_,85:_,95:_,100:_

Indicate which equation has infinitely many real solutions.

A.   $\frac{5}{20x}=\frac{1}{4x}$  

B.  $3x=4+5x$  

C.  $\sqrt{2x+3}+6=0$  

• A

• B

• C