Question

Explain how to solve 5x2-3x = 25 by completing the square. What are the solutions?

Answer 1

You're going to multiply 5 times 2
= 10
then it will be 10-3x=25
move the 10 to the other side
which will be
-3x=25-10 note when moving it to the other side the signs change meaning it'll be negative
25-10=15
-3x =15
then ur going to divide -3 divided by -3 cancelled each other out and 15divided by-3 which gives u
-5
your answer will be
x= -5

Answer 2

x= 3 +√509/10

Or

x= 3 - √509/10

Explanation:

Given:

5x2-3x = 25

Using completing the square method of solving quadratic equation

Step 1: Factor out the coefficient of the x^2 term.

5(x^2 - 3x/5) = 25

Step 2: Add a number that would complete the square inside the parenthesis and also add this to the other side of the equation.

Take (1/2) of (3/5)

1/2 × 3/5

= 3/10

Square 3/10

We have, 9/100

We have,

5(x^2 - 3x/5 + 9/100) = 25 + 9/100

Step 3: Simplify

x^2 - (3/5)x + 9/100 = 25 + 9/100

5(x^2 - 3x/5 + 9/100) = 5 + 9/20

Step 4:

factor the right side

(x - 3/10)^2 = 509/100

Take both roots

√ (x - 3/10)^2 = √509/100

x - 3/10 = ±√ [509/100]

x = [ 3 ±√509 ] / 10

x= 3+√509/10

Or

x= 3 - √509/10