220k views
4 votes
Oline is solving the equation 0 = x2 – 5x – 4 using the quadratic formula. Which value is the negative real number solution to her quadratic equation? Round to the nearest tenth if necessary. Quadratic formula: x = StartFraction negative b plus or minus StartRoot b squared minus 4 a c EndRoot Over 2 a EndFraction

User Hera
by
4.9k points

2 Answers

0 votes

Answer: D.–0.7

Step-by-step explanation: hope this helps :)

User Anjelina
by
5.4k points
4 votes

Answer:

The solution to the equation are
5+(√(42) )/(2\\) \ and \ 5-(√(42) )/(2\\)\\

Both of his values are positive real numbers

Explanation:

The general formula of a quadratic equation is expressed as
ax^(2)+bx+c = 0\ where;\\x = -b\±\frac{\sqrt{b^(2)-4ac } }{2a}

Given the expression 0 = x² – 5x – 4 which can be rewritten as shown below;

x² – 5x – 4 = 0

Comparing this to the general equation; a = 1, b = -5, c= -4

To get the solution to the quadratic equation, we will use the general formula above;


x = -b\±\frac{\sqrt{b^(2)-4ac } }{2a}\\x = -(-5)\±\frac{\sqrt{(-5)^(2)-4(1)(-4) } }{2(1)}\\\\x = 5\±(√(25+16 ) )/(2)\\x =5\±(√(41) )/(2)\\x = 5+(√(42) )/(2)\ and \ 5-√(42) /2\\

Both of his values are positive real numbers

User Lucas Teixeira
by
5.3k points