Question

What is (x+5)(x-4)=0 Expand and solve for x

Answer 1

step 1

(x - 4) • (x + 5) = 0

STEP

:

A product of several terms equals zero.

When a product of two or more terms equals zero, then at least one of the terms must be zero.

We shall now solve each term = 0 separately

Solving a Single Variable Equation:

2.2 Solve : x-4 = 0

Add 4 to both sides of the equation :

x = 4

Solving a Single Variable Equation:

2.3 Solve : x+5 = 0

Subtract 5 from both sides of the equation :

x = -5

.

Answer 2

A)
`\huge\boxed{\sf x^2 + x - 20 = 0}`

B)
`\huge\boxed{\sf x = - 5 \ \ \ \ OR \ \ \ \ x = 4}`

Explanation:

`\sf (x+5)(x-4) = 0`

`\rule[225]{225}{2}`

Expanding:

Expanding Brackets

`\sf x^2 -4x+5x-20 = 0`

Adding / Subtracting Like terms

`\sf x^2 + x - 20 = 0`

`\rule[225]{225}{2}`

Solving:

Given the equation:

(x+5)(x-4) = 0

Using zero Method

Either,

x + 5 = 0 OR x - 4 = 0

x = - 5 OR x = 4

`\rule[225]{225}{2}`