# maths

posted by .

solve the following equation by completing the square

x(square) -13x + 21 = 0

Then x= or x=

• maths -

x^2-13x+21 = 0
x^2-13x+(13/2)^2 + 21 - (13/2)^2 = 0
(x - 13/2)^2 - 85/4 = 0
x - 13/2)^2 = 85/4
x - 13/2 = ±√85/2
x = (13±√85)/2

## Similar Questions

1. ### Algebra

Can you pleas Solve the quadric equation step by step 4x square =13x+2 4x^2 = 13x + 2 subtract 13x and 2 from both sides 4x^2 - 13x - 2 = 0 Now use the quadratic formula, since it does not factor.
2. ### Algebra 2

Completing the square method allows you to solve any quadratic equation. For each of the following determine what number completes the square. I cannot find my notes on completing the square, can someone please help with these two …
3. ### Algebra

Completing the square method allows you to solve any quadratic equation. For each of the following determine what number completes the square. I cannot find my notes on completing the square, can someone please help with these two …
4. ### Math

Solve the following equation. 4.7 = 1.13x^2 Do i square root the 1.13x^2 first?
5. ### maths --plse help me..

solve the following equation by method of completing the perfect square:- 4x^2 + 4 √3 x +3=0
6. ### maths

solve the following equation by completing square x(square) + 5x - 84 Pls show steps x= or x=
7. ### maths

solve the following equation by completing the square x(square) - 4(square root 5)x =6 = 0 Then x= or x=
8. ### maths

Consider the equation x(square) + 4px + 2q = 0 where p and q are real constants. a) by completing square, show that (x+2p)square =4P(SQUARE)-2q b) Hence show that x= -2p +/- square root(4 p(square) -2p ) c) Use the above results to …
9. ### Algebra

Which of the following statements is true?