157k views
16 votes
Consider this quadratic equation.

x + 2x + 7 = 21
The number of positive solutions to this equation is ____
The approximate value of the greatest solution to the equation, rounded to the nearest hundredth, is _____

User AndrewJE
by
3.5k points

2 Answers

9 votes

Answer:

The number of positive solutions to this equation is

1

The approximate value of the greatest solution to the equation, rounded to the nearest hundredth, is

2.87

Explanation:

User Christian Pekeler
by
3.9k points
10 votes

Answer:

1 solution

2.88

Explanation:

Consider this quadratic equation.

x ^2+ 2x + 7 = 21

Subtract 7 from both sides

x ^2+ 2x + 7 -7= 21-7

x^2+2x = 14

x^2+2x -14 = 0

Factorize

x = -2±√2²-4(-14)/2

x= -2±√4+56/2

x = -2±√60/2

x = -2±7.75/2

x = -2-7.75/2 and -2+7.75/2

x = -9.75/2 and 5.75/2

x = -4.88 and 2.88

Hence there are 1 number of positive solution

The approximate value of the greatest solution to the equation, rounded to the nearest hundredth, is 2.88

User Satwik Nadkarny
by
3.6k points