Question

X^2-4x-5x=0

`x {2} - 4x - 5x = 0`
​

Answer 1

x = 9

or

x = 0

Explanation:

Step by step solution :

Step 1 :

Step 2 :

Pulling out like terms :

2.1 Pull out like factors :

x2 - 9x = x • (x - 9)

Equation at the end of step 2 :

x • (x - 9) = 0

Step 3 :

Theory - Roots of a product :

3.1 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

In other words, we are going to solve as many equations as there are terms in the product

Any solution of term = 0 solves product = 0 as well.

Solving a Single Variable Equation :

3.2 Solve : x = 0

Solution is x = 0

Solving a Single Variable Equation :

3.3 Solve : x-9 = 0

Add 9 to both sides of the equation :

x = 9

Answer 2

x = 9 or x = 0

Explanation:

Solve for x over the real numbers:

x^2 - 4 x - 5 x = 0

x^2 - 4 x - 5 x = x^2 - 9 x:

x^2 - 9 x = 0

Factor x from the left hand side:

x (x - 9) = 0

Split into two equations:

x - 9 = 0 or x = 0

Add 9 to both sides:

Answer: x = 9 or x = 0