Expanding Double Brackets

First, multiply $x$ by $x$ to get $x^2$, then multiply $x$ by 2 to get $2x$. Next, multiply 3 by $x$ to get $3x$, and 3 by 2 to get 6. Finally, add all the terms together: $x^2+2x+3x+6=x^2+5x+6$.

First, multiply $x$ by $x$ to get $x^2$, then multiply $x$ by 1 to get $x$. Next, multiply 4 by $x$ to get $4x$, and 4 by 1 to get 4. Combining like terms gives $x^2+x+4x+4=x^2+5x+4$.

First, multiply $2x$ by $x$ to get $2x^2$, then multiply $2x$ by 4 to get $8x$. Next, multiply 1 by $x$ to get $x$, and 1 by 4 to get 4. Combining all terms gives $2x^2+8x+x+4=2x^2+9x+4$.

First, multiply $x$ by $2x$ to get $2x^2$, then multiply $x$ by -3 to get $-3x$. Next, multiply -2 by $2x$ to get $-4x$, and -2 by -3 to get 6. Combining like terms gives $2x^2-3x-4x+6=2x^2-7x+6$.

First, multiply $3x$ by $x$ to get $3x^2$, then multiply $3x$ by 4 to get $12x$. Next, multiply -2 by $x$ to get $-2x$, and -2 by 4 to get -8. Combining like terms gives $3x^2+12x-2x-8=3x^2+10x-8$.

First, multiply $-5x$ by 4 to get $-20x$, then multiply $-5x$ by $-2x$ to get $10x^2$. Next, multiply 3 by 4 to get 12, and 3 by $-2x$ to get $-6x$. Combining all terms gives $10x^2-20x-6x+12=10x^2-26x+12$.