4a^2-9a+21=8

Simple and best practice solution for 4a^2-9a+21=8 equation. Check how easy it is, and learn it for the future. Our solution is simple, and easy to understand, so don`t hesitate to use it as a solution of your homework.

If it's not what You are looking for type in the equation solver your own equation and let us solve it.

Solution for 4a^2-9a+21=8 equation:


Simplifying
4a2 + -9a + 21 = 8

Reorder the terms:
21 + -9a + 4a2 = 8

Solving
21 + -9a + 4a2 = 8

Solving for variable 'a'.

Reorder the terms:
21 + -8 + -9a + 4a2 = 8 + -8

Combine like terms: 21 + -8 = 13
13 + -9a + 4a2 = 8 + -8

Combine like terms: 8 + -8 = 0
13 + -9a + 4a2 = 0

Begin completing the square.  Divide all terms by
4 the coefficient of the squared term: 

Divide each side by '4'.
3.25 + -2.25a + a2 = 0

Move the constant term to the right:

Add '-3.25' to each side of the equation.
3.25 + -2.25a + -3.25 + a2 = 0 + -3.25

Reorder the terms:
3.25 + -3.25 + -2.25a + a2 = 0 + -3.25

Combine like terms: 3.25 + -3.25 = 0.00
0.00 + -2.25a + a2 = 0 + -3.25
-2.25a + a2 = 0 + -3.25

Combine like terms: 0 + -3.25 = -3.25
-2.25a + a2 = -3.25

The a term is -2.25a.  Take half its coefficient (-1.125).
Square it (1.265625) and add it to both sides.

Add '1.265625' to each side of the equation.
-2.25a + 1.265625 + a2 = -3.25 + 1.265625

Reorder the terms:
1.265625 + -2.25a + a2 = -3.25 + 1.265625

Combine like terms: -3.25 + 1.265625 = -1.984375
1.265625 + -2.25a + a2 = -1.984375

Factor a perfect square on the left side:
(a + -1.125)(a + -1.125) = -1.984375

Can't calculate square root of the right side.

The solution to this equation could not be determined.

See similar equations:

| 7x+0.8=6.4 | | z-6.5=5.9 | | 15=5-3x | | 6p-1p= | | 1+-0.33y=0.7142+-0.4286y | | x+(x*2)=96 | | 2/5=×-2/20 | | t=3.5n | | ((-600)/x)^2=0,6/x | | 0.4x=2x | | 6/y==3/7 | | 2x^2+14x=-14 | | 82-4x=42 | | x^2+184=103 | | (9x^6)(y^5)-(8x^4)(y^3)= | | 40=2X+2X^2 | | (3^7)/(3^5) | | -2b^2+10b+4=-8b^2 | | 250/1-250/3 | | X=2y^2-14y-3 | | Y=80(200)+4000 | | 6x-3x^2-2=0 | | 88/0.2= | | Y=80(100)+4000 | | 5x-6(3+2x)= | | (-600)/x=(0,6)/x^2 | | 6x+3-2x=3x-6 | | 250-250/3 | | 3(1+105x)=8 | | x(9-4)=13 | | 4i=96 | | 200y=50000 |

Equations solver categories