<span>Simplifying
3a2 + -2a + -1 = 0
Reorder the terms:
-1 + -2a + 3a2 = 0
Solving
-1 + -2a + 3a2 = 0
Solving for variable 'a'.
Factor a trinomial.
(-1 + -3a)(1 + -1a) = 0
Subproblem 1Set the factor '(-1 + -3a)' equal to zero and attempt to solve:
Simplifying
-1 + -3a = 0
Solving
-1 + -3a = 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 + -3a = 0 + 1
Combine like terms: -1 + 1 = 0
0 + -3a = 0 + 1
-3a = 0 + 1
Combine like terms: 0 + 1 = 1
-3a = 1
Divide each side by '-3'.
a = -0.3333333333
Simplifying
a = -0.3333333333
Subproblem 2Set the factor '(1 + -1a)' equal to zero and attempt to solve:
Simplifying
1 + -1a = 0
Solving
1 + -1a = 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 + -1a = 0 + -1
Combine like terms: 1 + -1 = 0
0 + -1a = 0 + -1
-1a = 0 + -1
Combine like terms: 0 + -1 = -1
-1a = -1
Divide each side by '-1'.
a = 1
Simplifying
a = 1Solutiona = {-0.3333333333, 1}</span>
Answer:
option d. is the correct answer
The x intercept would be on (-2,0)
We have similar triangles so
12/x = (12+78)/(x+13)
We can skip some algebra by doing the ratio on the pieces. We'll show it works at the end.
12/x = 78/13
x = 12(13)/78 = 2
We check
12/2 = 6
(12+78)/(2+13) = 90/15 = 6, good
Answer: x=2
