yaredmitiku41
Answered

solve each of the following quadratic inequalities using any Convenient
method :
A)
[tex]x(10x + 19) \leqslant 15[/tex]
[tex](x + 2)^{2} > (3x + 1)^{2} [/tex]
​



Answer :

sqdancefan

Answer:

  • -2.5 ≤ x ≤ 0.6
  • -0.75 < x < 0.5

Step-by-step explanation:

You want the solutions to the following inequalities by any convenient method:

  • x(10x +19) ≤ 15
  • (x +2)² > (3x +1)²

Comparison

We choose to rewrite these inequalities to be comparisons to zero. This is because our graphing calculator easily identifies the x-intercepts of a graph. We can look a the graph to tell where the function is above or below the x-axis.

  • f(x) = x(10x +19) -15; f(x) ≤ 0
  • g(x) = (x +2)² -(3x +1)²; g(x) > 0

Graph

The attached graph shows the solutions to be ...

  • f(x) ≤ 0 for -2.5 ≤ x ≤ 0.6
  • g(x) > 0 for -0.75 < x < 0.5
View image sqdancefan

The values obtained for the first equation will be  x ≤ 3/5 and x ≤ -5/2 and the values obtained for the second equation will be x < 1/2 and x < -3/4.

What is inequality?

Inequalities are mathematical expressions where neither side is equal. In inequality, as opposed to equations, we compare the two values. Less than (or less than and equal to), larger than (or greater or equal to), or not similar to signs are used in place of the equal sign in between.

As per the given inequalities in the question,

1.

x(10x + 19) ≤ 15

Firstly, simplify it to the simpler form,

10x² + 19x - 15 ≤ 0

Solve the quadratic equation,

D = b² - 4ac

= 19² - 4(10)(-15).

D = 961

Now, use the formula,

(-b±√D)/2a

√D = √961 = 31

(-19 ± 31)/2(10)

So, the roots are:

1.

(-19 + 31)/20 = 12/20 = 3/5

Or, x ≤ 3/5

2.

(-19 - 31)/20 = -50/20 = -5/2

Or, x ≤ -5/2

2.

(x + 2)² > (3x + 1)²

Simplify the equation first.

x² + 4x + 4 > 9x² + 6x + 1

x² - 9x² + 4x - 6x + 4 - 1 > 0

-8x² - 2x + 3 >

8x² + 2x - 3 < 0

Now, find the roots for the equation,

D = b² - 4ac

D = 4 + 96

D = 100

Now, use the formula,

(-b ± √D)/2a

(-2 ± 10)/16

So, the roots are:

1. (-2 + 10)/16 = 1/2

Or, x < 1/2

2. (-2 - 10)/16 = -12/16 = -3/4

Or, x < -3/4

To know more about Inequality:

https://brainly.com/question/28823603

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