Question
Crawford County, Iowa, is shaped like a rectangle. The length of the county is 6 miles longer than the width of the county. If \(A(x)\) is the area of the county, in square miles, and \(x\) is the width, in miles, which equation best models the area of the county?
- \(A(x) = x(6x)\)
- \(A(x) = x(6 – x)\)
- \(A(x) = x(x – 6)\)
- \(A(x) = x(x + 6)\)
Answer/Explanation
Ans: D
Question
Which of the following expressions is equivalent to \(x^2+ 10x + 21\) ?
- \( (x+ 1)(x+ 9) + 12 \)
- \((x + 1)(x + 9) + 12x\)
- \( (x+3)(x+ 7) + 5\)
- \((x + 3)(x + 7) + 5x\)
Answer/Explanation
Ans: A
Question
Which of the following is an equivalent form of the expression \((2x — 2)^2 — (2x — 2)\) ?
- \(2x^2 — 6x + 6\)
- \(4x^2 — 10x + 2\)
- \((2x — 2)(2x — 2)\)
- \( (2x — 3)(2x — 2)\)
Answer/Explanation
Ans: D
Question
\((3x+2)(2x+3)\)
Which of the following is equivalent to the expression above?
- \(3x^2 + 10x+5\)
- \(5x^2 + 13x+ 5\)
- \(6x^2 + 13x+6\)
- \(6x^2 +15x+9\)
Answer/Explanation
Ans: C
Question
Which of the following is equivalent to \((2x + 4)^2 – 4x^2\) ?
- \(16(x+1)\)
- \(8(x+ 2)\)
- \(4(4x + 1)\)
- \(2(8x + 1) \)
Answer/Explanation
Ans: A
Question
If \(3x-6y=9z\), which of the following expressions is equivalent to \(x^2-4xy+4y^2\)?
- \(9z\)
- \(3z^2\)
- \(9z^2\)
- \(81z^2\)
Answer/Explanation
Ans: C
Question
\(x(x + 1) + 2(x + 1) = ax^2 +bx+ c\)
In the equation above, \(a, b\), and \(c\) are constants. If the equation is true for all values of \(x\), what is the value of \(a + b + c \)?
- 6
- 5
- 4
- 3
Answer/Explanation
Ans: A