All questions
Question 1
If f(x)=x2−9x2−4x+3 and g(x)=x2−2x−3x2+x−12, what is f(x)⋅g(x) in simplest form?
- (x+3)(x+1)(x−1)(x+4) (correct answer)
- x+3x−1
- x+1x+4
- (x+3)(x+1)(x−3)(x+4)
Explanation: First factor each polynomial: x2−4x+3=(x−1)(x−3), x2−9=(x−3)(x+3), x2+x−12=(x+4)(x−3), and x2−2x−3=(x−3)(x+1). So f(x)=(x−3)(x+3)(x−1)(x−3)=x+3x−1 and g(x)=(x−3)(x+1)(x+4)(x−3)=x+1x+4. Therefore, f(x)⋅g(x)=x+3x−1⋅x+1x+4=(x+3)(x+1)(x−1)(x+4).
Question 2
Which expression represents x2−x−2x2+5x+6÷x2−4x2+4x+3 in lowest terms?
- (x+1)2(x+2)(x−2)
- x+1x+2
- x+1x−2 (correct answer)
- (x+1)(x−1)(x+3)(x−2)
Explanation: Convert to multiplication: x2−x−2x2+5x+6⋅x2+4x+3x2−4. Factor each polynomial: x2+5x+6=(x+2)(x+3), x2−x−2=(x−2)(x+1), x2−4=(x−2)(x+2), and x2+4x+3=(x+1)(x+3). The expression becomes (x−2)(x+1)(x+2)(x+3)⋅(x+1)(x+3)(x−2)(x+2). Cancel (x+2), (x+3), and (x+1) to get x+1x−2.
Question 3
Which expression is equivalent to x2−25x2+3x−10⋅x2−4x+4x2−10x+25?
- x−2x−5 (correct answer)
- x+5x+2
- (x+5)(x−2)(x+2)(x−5)
- x−2x+5
Explanation: Factor each polynomial: x2+3x−10=(x+5)(x−2), x2−25=(x−5)(x+5), x2−10x+25=(x−5)2, and x2−4x+4=(x−2)2. The expression becomes (x−5)(x+5)(x+5)(x−2)⋅(x−2)2(x−5)2. Cancel (x+5) and one factor of (x−2) and one factor of (x−5) to get x−2x−5.
Question 4
Simplify x2+2x+4x3−8÷x2+4x+4x2−4.
- (x+2)(x−2)(x−2)(x+2)2
- x−2x+2
- x+2x−2
- x+2 (correct answer)
Explanation: Convert division to multiplication: x2+2x+4x3−8⋅x2−4x2+4x+4. Factor using difference of cubes and other patterns: x3−8=(x−2)(x2+2x+4), x2+4x+4=(x+2)2, and x2−4=(x−2)(x+2). The expression becomes x2+2x+4(x−2)(x2+2x+4)⋅(x−2)(x+2)(x+2)2. Cancel (x2+2x+4), (x−2), and one factor of (x+2) to get x+2.