# Discriminant

Use the discriminant to determine how many real-number solutions the equation has 1 - 7a2 = -7a - 2

A) 2
B) 1
C) 0
Not sure how to work this problem

1. 👍 0
2. 👎 0
3. 👁 105
1. rearrange it.

7a^2+7a+2=0

discriminate= 49-4*7*2= negative number, no real solutions.

1. 👍 0
2. 👎 0
2. First arrange the terms in the standard form of a quadratic:
1 - 7a2 = -7a - 2
7a²-7a-3=0
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
D=(B²-4AC)
and the roots of the equation are:
X1,X2= (-B±√(B²-4AC))/2A
Therefore
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".

1. 👍 0
2. 👎 0
3. 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.
They are
x = (1/14)(7 +/- sqrt(133)]= 1.324 and
-0.324

1. 👍 0
2. 👎 0
posted by drwls
4. 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

1. 👍 0
2. 👎 0
posted by Lisa D
5. -133 should be 133 in my previous answer.
There is NOT one root. There are two, if I did the numbers right.

1. 👍 0
2. 👎 0
posted by drwls
6. Ok, I got it. Sorry been having problems w/ this site.Thanks I got more..

1. 👍 0
2. 👎 0
posted by Lisa D

## Similar Questions

1. ### Math

Use the discriminant to determine how many real-number solutions the equation has. Problem 1 w2 - 2w + 2 = 0 A) 2 B) 1 C) 0 Problem 2 1 - 7a2 = -7a - 2 A) 2 B) 1 C) 0

asked by Sharee on August 5, 2010
2. ### Math

Can someone please check my work for me? Write an equation of the line satisfying the given conditions. 9) Intersects the line y = 2 + 3x at infinitely many places. 9) A) y = -3x + 2 B) y = 2x + 3 C) y = -1/3x + 2 D) y = 2 + 3x Is

asked by Nicole on May 16, 2010
3. ### Math

For the following equation, state the value of the discriminant and then describe the nature of the solutions. -9x^2+6x-2=0 what is the value of the discriminant? Which one of the statements below is correct? A) the equation has

asked by Allison Anderson on November 29, 2011
4. ### algebra

For the following equation, state the value of the discriminant and then describe the nature of the solutions. -2x^2+3x-7=0 What is the value of the discriminant? Which one of the statements below is correct? The equation has two

asked by Becky on March 21, 2008
5. ### Algebra Problem

State the value of the discriminant and the number of real solutions. t^2+14t+49=0 The value of the discriminant is 0 and the equation has no real solution.

asked by Jim on March 21, 2008
6. ### math

Use the discriminant to determine how many real-number solutions the equation has. v^2 - 7v + 5 = 0

asked by chandice on November 8, 2009
7. ### Algebra

Use the discriminant to determine how many real number solutions the equation has. t^2 + 8t + 16 = 0

asked by Don on May 23, 2010
8. ### algebra

Use the discriminant to determine how many real-number solutions the equation has. s2 - 5s + 6 = 0

asked by Abby on May 16, 2010
9. ### math

Use the discriminant to determine how many real-number solutions the equation has. v2 - 7v + 5 = 0

asked by jeng on November 15, 2009
10. ### Equation

w2 - 2w + 2 = 0 Use the discriminant to determine how many real-number solutions the equation has A.2 B.1 C.0

asked by Lisa D on June 27, 2010

More Similar Questions