Lesson
VIDEO
Problems & Videos
\(\textbf{1)}\) \(\hspace{1ex} 2x(x-3) \) The answer is \( 2x^2-6x \)
\(2x(x-3)\)
\(2x\cdot x-2x\cdot3\)
\(2x^2-6x\)
\(\,\)The answer is \(2x^2-6x\)
\(\textbf{2)}\) \(\hspace{1ex} (x+2)(x-5) \) The answer is \( x^2-3x-10 \)
\((x+2)(x-5)\)
\(x(x-5)+2(x-5)\)
\(x^2-5x+2x-10\)
\(x^2-3x-10\)
\(\,\)The answer is \(x^2-3x-10\)
\(\textbf{3)}\) \(\hspace{1ex} (x+4)(x-4) \) The answer is \( x^2-16 \)
\((x+4)(x-4)\)
\(x(x-4)+4(x-4)\)
\(x^2-4x+4x-16\)
\(x^2-16\)
\(\,\)The answer is \(x^2-16\)
\(\textbf{4)}\) \(\hspace{1ex} (x+2)(x^2+3x-5) \) The answer is \( x^3+5x^2+x-10 \)
\((x+2)(x^2+3x-5)\)
\(x(x^2+3x-5)+2(x^2+3x-5)\)
\(x^3+3x^2-5x+2x^2+6x-10\)
\(x^3+5x^2+x-10\)
\(\,\)The answer is \(x^3+5x^2+x-10\)
\(\textbf{5)}\) \(\hspace{1ex} (2x-3)(3x+4) \)
The answer is \( 6x^2-x-12 \)
\((2x-3)(3x+4)\)
\(2x(3x+4)-3(3x+4)\)
\(6x^2+8x-9x-12\)
\(6x^2-x-12\)
\(\,\)The answer is \(6x^2-x-12\)
\(\textbf{6)}\) \(\hspace{1ex} (t-5)^2 \)
The answer is \( t^2-10t+25 \)
\((t-5)^2\)
\((t-5)(t-5)\)
\(t^2-5t-5t+25\)
\(t^2-10t+25\)
\(\,\)The answer is \(t^2-10t+25\)
\(\textbf{7)}\) \(\hspace{1ex} (x+5)^3 \)
The answer is \( x^3+15x^2+75x+125 \)
\((x+5)^3\)
\((x+5)(x+5)^2\)
\((x+5)(x^2+10x+25)\)
\(x(x^2+10x+25)+5(x^2+10x+25)\)
\(x^3+10x^2+25x+5x^2+50x+125\)
\(x^3+15x^2+75x+125\)
\(\,\)The answer is \(x^3+15x^2+75x+125\)
\(\textbf{8)}\) \(\hspace{1ex} (x+5)(2x^2-3x+2) \)
The answer is \( 2x^3+7x^2-13x+10 \)
\((x+5)(2x^2-3x+2)\)
\(x(2x^2-3x+2)+5(2x^2-3x+2)\)
\(2x^3-3x^2+2x+10x^2-15x+10\)
\(2x^3+7x^2-13x+10\)
\(\,\)The answer is \(2x^3+7x^2-13x+10\)
\(\textbf{9)}\) \(\hspace{1ex} 4x(2x+5) \) The answer is \( 8x^2+20x \)
\(4x(2x+5)\)
\(4x\cdot2x+4x\cdot5\)
\(8x^2+20x\)
\(\,\)The answer is \(8x^2+20x\)
\(\textbf{10)}\) \(\hspace{1ex} (x+2)(x-2) \) The answer is \( x^2-4 \)
\((x+2)(x-2)\)
\(x(x-2)+2(x-2)\)
\(x^2-2x+2x-4\)
\(x^2-4\)
\(\,\)The answer is \(x^2-4\)
\(\textbf{11)}\) \(\hspace{1ex} (x+1)(x+3) \) The answer is \( x^2+4x+3 \)
\((x+1)(x+3)\)
\(x(x+3)+1(x+3)\)
\(x^2+3x+x+3\)
\(x^2+4x+3\)
\(\,\)The answer is \(x^2+4x+3\)
\(\textbf{12)}\) \(\hspace{1ex} (x+3)(2x^2+4x-4) \) The answer is \( 2x^3+10x^2+8x-12 \)
\((x+3)(2x^2+4x-4)\)
\(x(2x^2+4x-4)+3(2x^2+4x-4)\)
\(2x^3+4x^2-4x+6x^2+12x-12\)
\(2x^3+10x^2+8x-12\)
\(\,\)The answer is \(2x^3+10x^2+8x-12\)
\(\textbf{13)}\) \(\hspace{1ex} (3x + 2)(2x – 5) \) The answer is \( 6x^2 – 11x – 10 \)
\((3x+2)(2x-5)\)
\(3x(2x-5)+2(2x-5)\)
\(6x^2-15x+4x-10\)
\(6x^2-11x-10\)
\(\,\)The answer is \(6x^2-11x-10\)
\(\textbf{14)}\) \(\hspace{1ex} (x – 3)(x + 4) \) The answer is \( x^2 + x – 12 \)
\((x-3)(x+4)\)
\(x(x+4)-3(x+4)\)
\(x^2+4x-3x-12\)
\(x^2+x-12\)
\(\,\)The answer is \(x^2+x-12\)
\(\textbf{15)}\) \(\hspace{1ex} (2x + 1)(3x – 2) \) The answer is \( 6x^2 – x – 2 \)
\((2x+1)(3x-2)\)
\(2x(3x-2)+1(3x-2)\)
\(6x^2-4x+3x-2\)
\(6x^2-x-2\)
\(\,\)The answer is \(6x^2-x-2\)
\(\textbf{16)}\) \(\hspace{1ex} (4x – 1)(x + 7) \) The answer is \( 4x^2 + 27x – 7 \)
\((4x-1)(x+7)\)
\(4x(x+7)-1(x+7)\)
\(4x^2+28x-x-7\)
\(4x^2+27x-7\)
\(\,\)The answer is \(4x^2+27x-7\)
\(\textbf{17)}\) \(\hspace{1ex} (2x + 5)(x – 3) \) The answer is \( 2x^2 – x – 15 \)
\((2x+5)(x-3)\)
\(2x(x-3)+5(x-3)\)
\(2x^2-6x+5x-15\)
\(2x^2-x-15\)
\(\,\)The answer is \(2x^2-x-15\)
\(\textbf{18)}\) \(\hspace{1ex} (x + 4)(3x + 1) \) The answer is \( 3x^2 + 13x + 4 \)
\((x+4)(3x+1)\)
\(x(3x+1)+4(3x+1)\)
\(3x^2+x+12x+4\)
\(3x^2+13x+4\)
\(\,\)The answer is \(3x^2+13x+4\)
\(\textbf{19)}\) \(\hspace{1ex} (2x – 3)(x + 6) \) The answer is \( 2x^2 + 9x – 18 \)
\((2x-3)(x+6)\)
\(2x(x+6)-3(x+6)\)
\(2x^2+12x-3x-18\)
\(2x^2+9x-18\)
\(\,\)The answer is \(2x^2+9x-18\)
\(\textbf{20)}\) \(\hspace{1ex} (x + 2)(2x^2 – 3x + 5) \) The answer is \( 2x^3 + x^2 – x + 10 \)
\((x+2)(2x^2-3x+5)\)
\(x(2x^2-3x+5)+2(2x^2-3x+5)\)
\(2x^3-3x^2+5x+4x^2-6x+10\)
\(2x^3+x^2-x+10\)
\(\,\)The answer is \(2x^3+x^2-x+10\)
See Related Pages\(\)
In Summary
Multiplying polynomials involves multiplying two or more algebraic expressions that consist of multiple terms. This process involves multiplying the coefficients and variables of each term, and combining like terms as necessary. Multiplying polynomials is typically taught in an algebra class. Students learn the basics of working with polynomials, including adding, subtracting, multiplying, and dividing them. These skills are essential for success in higher level math classes, such as geometry, trigonometry, and calculus. In the real world, multiplying polynomials is used in a variety of contexts, including engineering, science, and finance.