i have an equation; x^2+3x-18=0. i am given one of the roots, of which is 3, but how do i find the other root.
The School Subject must be labeled correctly. 10th grade is not the proper School Subject.
Sra
its easy. do you know how to use the quadratic equation? plug the values for A,B, and C into the equation and see whatcha get.
To find the other root of the equation x^2 + 3x - 18 = 0 when one root is given, you can use the fact that the sum of the roots of a quadratic equation is equal to the negation of the coefficient of the linear term (x-term) divided by the coefficient of the quadratic term (x^2-term).
Given that one root is 3, the sum of the roots is -3. Now, you can calculate the other root using the formula. Let's assume the other root is denoted as r.
Sum of the roots = -3
Root 1 + Root 2 = -3
3 + r = -3
Now, solve for r:
r = -3 - 3
r = -6
So, the other root of the equation x^2 + 3x - 18 = 0 is -6.
You can also verify this result by substituting both roots into the original equation to ensure they satisfy it:
For root 1 (3):
(3)^2 + 3(3) - 18 = 0
9 + 9 - 18 = 0
18 - 18 = 0
0 = 0 (satisfied)
For root 2 (-6):
(-6)^2 + 3(-6) - 18 = 0
36 - 18 - 18 = 0
18 - 18 = 0
0 = 0 (satisfied)
Therefore, both roots, 3 and -6, satisfy the equation x^2 + 3x - 18 = 0.