posted by Lisa D on .
Use the discriminant to determine how many real-number solutions the equation has 1 - 7a2 = -7a - 2
Not sure how to work this problem
discriminate= 49-4*7*2= negative number, no real solutions.
First arrange the terms in the standard form of a quadratic:
1 - 7a2 = -7a - 2
The variable is a, and the coefficients of the a², a and constant terms are respectively
A=7, B=-7, C=-3
The discriminant is the expressino
and the roots of the equation are:
if D>0, there are two roots, if D=0, there is one root (actually two coincident roots), and if D<0, the roots are complex, or generally considered "no root".
Post your answer for checking if you wish.
Rewrite your equation in standard form:
7a^2 -7a -3 = 0
They are trying to confuse you by using a as a variable. Think of your equation as
7x^2 -7x -3 = 0
It does not matter what symbol you giove to the unknown variable; just don't call it "a".
The numbers a, b, and c in the equation are 7, -7 and -3.
The discriminant is b^2 -4ac = 49+84 = -133
Since it is positive, there are two real solutions.
x = (1/14)(7 +/- sqrt(133)]= 1.324 and
Thanks for the Explaning this problem drwls. Ok, the first time I worked the problem I got 0 then I reworked it and got 1
-133 should be 133 in my previous answer.
There is NOT one root. There are two, if I did the numbers right.
Ok, I got it. Sorry been having problems w/ this site.Thanks I got more..