Answer:
x = 4, -7
Step-by-step explanation:
1. <u>Solve the equation using the quadratic formula</u>
The <u>Quadratic formula</u> provides the solution for 
in which A, B, and C are numbers (or coefficients), as follows:

2. <u>Determine the quadratic equation’s coefficients A, B, and C</u>
The <u>coefficients</u> of our equation,
, are:
A = 5
B = 15
C = -140
3. <u>Plug these coefficients into the quadratic formula</u>
<u />
Calculate the expression inside the parentheses.
Simplify exponents and square roots.


Perform any multiplication or division, from left to right.




to get the result:

4. <u>Simplify square root</u>
Simplify 3025 by finding its prime factors.
3025
/ \
/ \
5 605
/ \
/ \
5 "<u>121</u>"
/ \
/ \
11 11
The prime factorization of 3025 is 5² • 11²
Write the prime factors.
= √5 • 5 • 11 • 11
Group the prime factors into pairs and rewrite in exponent form.
√5 • 5 • 11 • 11 = 
Use rule
= x to simplify futher.
= 5 • 11
5 • 11 = 55
5. Solve the equation for x
x = 
The ± means two answers are possible:
x = 4
or
x = - 7