Select the two values of x that are roots of this equation.x2 + 3x – 5 = 0
Mathematics · High School · Tue Nov 03 2020
Answered on
Given the quadratic equation:
x^2 + 3x - 5
a = 1
b = 3
c = -5
Solve for the roots.
Solution:
In order to solve for the roots of an equation, we simply must look at the 2nd and 3rd value. First we must think of two numbers that when added, the answer is 3, and when multiplied, the answer is -5. Hence, if we are unable to find the number, we will use the quadratic formula.
Quadratic formula:
x = −b ± √(b^2 − 4ac)/2a
x = −3 ± √((3)^2 − (4)(1)(-5))/2(1)
x = −3 ± √(9 − (-20)/2
x = −3 ± √(9 + 20)/2
x = −3 ± √(29)/2
x = −3 ± 5.4 / 2
Solve for ± individually.
x = −3 + 5.4 / 2
x = 2.4 / 2
x = 1.2
x= -3 - 5.4 /2
x =- 8.4/2
x = -4.2
Final answer:
x = 1.2
x = -4.2