2a^2-15a-18=0

Simple and best practice solution for 2a^2-15a-18=0 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 2a^2-15a-18=0 equation:


Simplifying
2a2 + -15a + -18 = 0

Reorder the terms:
-18 + -15a + 2a2 = 0

Solving
-18 + -15a + 2a2 = 0

Solving for variable 'a'.

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

Divide each side by '2'.
-9 + -7.5a + a2 = 0

Move the constant term to the right:

Add '9' to each side of the equation.
-9 + -7.5a + 9 + a2 = 0 + 9

Reorder the terms:
-9 + 9 + -7.5a + a2 = 0 + 9

Combine like terms: -9 + 9 = 0
0 + -7.5a + a2 = 0 + 9
-7.5a + a2 = 0 + 9

Combine like terms: 0 + 9 = 9
-7.5a + a2 = 9

The a term is -7.5a.  Take half its coefficient (-3.75).
Square it (14.0625) and add it to both sides.

Add '14.0625' to each side of the equation.
-7.5a + 14.0625 + a2 = 9 + 14.0625

Reorder the terms:
14.0625 + -7.5a + a2 = 9 + 14.0625

Combine like terms: 9 + 14.0625 = 23.0625
14.0625 + -7.5a + a2 = 23.0625

Factor a perfect square on the left side:
(a + -3.75)(a + -3.75) = 23.0625

Calculate the square root of the right side: 4.802343178

Break this problem into two subproblems by setting 
(a + -3.75) equal to 4.802343178 and -4.802343178.

Subproblem 1

a + -3.75 = 4.802343178 Simplifying a + -3.75 = 4.802343178 Reorder the terms: -3.75 + a = 4.802343178 Solving -3.75 + a = 4.802343178 Solving for variable 'a'. Move all terms containing a to the left, all other terms to the right. Add '3.75' to each side of the equation. -3.75 + 3.75 + a = 4.802343178 + 3.75 Combine like terms: -3.75 + 3.75 = 0.00 0.00 + a = 4.802343178 + 3.75 a = 4.802343178 + 3.75 Combine like terms: 4.802343178 + 3.75 = 8.552343178 a = 8.552343178 Simplifying a = 8.552343178

Subproblem 2

a + -3.75 = -4.802343178 Simplifying a + -3.75 = -4.802343178 Reorder the terms: -3.75 + a = -4.802343178 Solving -3.75 + a = -4.802343178 Solving for variable 'a'. Move all terms containing a to the left, all other terms to the right. Add '3.75' to each side of the equation. -3.75 + 3.75 + a = -4.802343178 + 3.75 Combine like terms: -3.75 + 3.75 = 0.00 0.00 + a = -4.802343178 + 3.75 a = -4.802343178 + 3.75 Combine like terms: -4.802343178 + 3.75 = -1.052343178 a = -1.052343178 Simplifying a = -1.052343178

Solution

The solution to the problem is based on the solutions from the subproblems. a = {8.552343178, -1.052343178}

See similar equations:

| 2t+1+2t-3t=6+2 | | c^2-8c-36= | | -29-7k=2(1k+8) | | x+3+2x+4+3x-7= | | 3x-x=26 | | 2a^2-15-18=0 | | 5x-23+x=7 | | 11=x/8 | | 4.8/0.6 | | 6.4s-9=5.4s-9 | | 9x-5+3x=31 | | -4(5v-1)+8v=8+3(2v-4) | | 3/x+4-7=18/x+4 | | 10y^5+28y^4-6y^3=0 | | 5k-(-9k)=-70 | | 3x+(3x+5)+(7x+6)=180 | | 4x+15-x=12 | | -8y+2=-9y+7 | | 2x^2+11xy+14y^2=0 | | 3a=0.39 | | 6+6x=8y | | 7+16y= | | 2x+12=3x+9 | | x/5=(x/11)+12 | | 2/3x+5/4=13/6x+5/3 | | 9a-(-72)= | | -5(w-2)=(-2)w-5 | | 2x^2-13xy-24y^2=0 | | -15-15= | | (x+6/9)=(x/6)+(1/2) | | -32-5n=7(n-8) | | (3x)/4+2=4x-1 |

Equations solver categories