expand (x+4)*(x-5) — step-by-step solution

Let's expand:

(x + 4) \cdot (x - 5)

ⓘ Expand by multiplying each term inside the parentheses:

(x + 4) \cdot (x - 5)

x \cdot x

+ x \cdot (-5)

+ 4 x

+ 4 \cdot (-5)

x \cdot x

+ x \cdot (-5)

+ 4 x

+ 4 \cdot (-5)

ⓘ Multiplying powers with the same base adds the exponents:

x \cdot x

x^{2}

■The minus sign is placed in front of the product:

x \cdot (-5)

- 5 x

■Multiplications are done before additions and subtractions. A single minus sign does not cancel out, the product of a negative number by a positive number is negative:

4 \cdot (-5)

-20

x^{2}

- 5 x

+ 4 x

- 20

ⓘ Like terms are grouped by adding their coefficients:

- 5 x + 4 x

- x

▶Expanded form:

x^{2} - x - 20