Find two numbers that . . .

1. multiply to -40 and add to -6.
2. multiply to -40 and add to 6.
3. multiply to -36 and add to 9.
4. multiply to -36 and add to -5.

If you get stuck, try listing all the factors of the first number.

Create a diagram to show that \((x-5)(x+8)\) is equivalent to \(x^2+3x-40\).

Write a \(+\) or a \(-\) sign in each box so the expressions on each side of the equal sign are equivalent.

1. \((x \; \boxed{\phantom{30}} \;18)(x \; \boxed{\phantom{30}} \; 3)=x^2-15x-54\)
2. \((x \; \boxed{\phantom{30}} \; 18)(x \; \boxed{\phantom{30}} \; 3)=x^2+21x+54\)
3. \((x \; \boxed{\phantom{30}} \; 18)(x \; \boxed{\phantom{30}} \; 3)=x^2+15x-54\)
4. \((x \; \boxed{\phantom{30}} \; 18)(x \; \boxed{\phantom{30}} \; 3)=x^2-21x+54\)