(5a-4)(7a+1)=

Solution for (5a-4)(7a+1)= equation:

Simplifying
(5a + -4)(7a + 1) = 0

Reorder the terms:
(-4 + 5a)(7a + 1) = 0

Reorder the terms:
(-4 + 5a)(1 + 7a) = 0

Multiply (-4 + 5a) * (1 + 7a)
(-4(1 + 7a) + 5a * (1 + 7a)) = 0
((1 * -4 + 7a * -4) + 5a * (1 + 7a)) = 0
((-4 + -28a) + 5a * (1 + 7a)) = 0
(-4 + -28a + (1 * 5a + 7a * 5a)) = 0
(-4 + -28a + (5a + 35a2)) = 0

Combine like terms: -28a + 5a = -23a
(-4 + -23a + 35a2) = 0

Solving
-4 + -23a + 35a2 = 0

Solving for variable 'a'.

Factor a trinomial.
(-1 + -7a)(4 + -5a) = 0

Subproblem 1
Set the factor '(-1 + -7a)' equal to zero and attempt to solve:

Simplifying
-1 + -7a = 0

Solving
-1 + -7a = 0

Move all terms containing a to the left, all other terms to the right.

Add '1' to each side of the equation.
-1 + 1 + -7a = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -7a = 0 + 1
-7a = 0 + 1

Combine like terms: 0 + 1 = 1
-7a = 1

Divide each side by '-7'.
a = -0.1428571429

Simplifying
a = -0.1428571429
Subproblem 2
Set the factor '(4 + -5a)' equal to zero and attempt to solve:

Simplifying
4 + -5a = 0

Solving
4 + -5a = 0

Move all terms containing a to the left, all other terms to the right.

Add '-4' to each side of the equation.
4 + -4 + -5a = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -5a = 0 + -4
-5a = 0 + -4

Combine like terms: 0 + -4 = -4
-5a = -4

Divide each side by '-5'.
a = 0.8

Simplifying
a = 0.8
Solution
a = {-0.1428571429, 0.8}