-3a-4a(2a+3)+7(a-5)=

Solution for -3a-4a(2a+3)+7(a-5)= equation:

Simplifying
-3a + -4a(2a + 3) + 7(a + -5) = 0

Reorder the terms:
-3a + -4a(3 + 2a) + 7(a + -5) = 0
-3a + (3 * -4a + 2a * -4a) + 7(a + -5) = 0
-3a + (-12a + -8a2) + 7(a + -5) = 0

Reorder the terms:
-3a + -12a + -8a2 + 7(-5 + a) = 0
-3a + -12a + -8a2 + (-5 * 7 + a * 7) = 0
-3a + -12a + -8a2 + (-35 + 7a) = 0

Reorder the terms:
-35 + -3a + -12a + 7a + -8a2 = 0

Combine like terms: -3a + -12a = -15a
-35 + -15a + 7a + -8a2 = 0

Combine like terms: -15a + 7a = -8a
-35 + -8a + -8a2 = 0

Solving
-35 + -8a + -8a2 = 0

Solving for variable 'a'.

Factor out the Greatest Common Factor (GCF), '-1'.
-1(35 + 8a + 8a2) = 0

Ignore the factor -1.
Subproblem 1
Set the factor '(35 + 8a + 8a2)' equal to zero and attempt to solve:

Simplifying
35 + 8a + 8a2 = 0

Solving
35 + 8a + 8a2 = 0

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

Divide each side by '8'.
4.375 + a + a2 = 0

Move the constant term to the right:

Add '-4.375' to each side of the equation.
4.375 + a + -4.375 + a2 = 0 + -4.375

Reorder the terms:
4.375 + -4.375 + a + a2 = 0 + -4.375

Combine like terms: 4.375 + -4.375 = 0.000
0.000 + a + a2 = 0 + -4.375
a + a2 = 0 + -4.375

Combine like terms: 0 + -4.375 = -4.375
a + a2 = -4.375

The a term is a.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
 + 0.25 + a2 = -4.375 + 0.25

Combine like terms:  + 0.25 = 1.25
1.25 + a2 = -4.375 + 0.25

Combine like terms: -4.375 + 0.25 = -4.125
1.25 + a2 = -4.125

Factor a perfect square on the left side:
(a + 0.5)(a + 0.5) = -4.125

Can't calculate square root of the right side.

The solution to this equation could not be determined.

This subproblem is being ignored because a solution could not be determined.

The solution to this equation could not be determined.