50

a quadratic equation is shown below: 3x^2 − 15x − 10 = 0

part a: describe the solution(s) to the equation by just determining the radicand. show your work.

part b: solve 4x^2 − 8x − 5 = 0 by using an appropriate method. show the steps of your work, and explain why you chose the method used.

two solutions x = 1 and x = - 8/3 x

Step-by-step explanation:

These are two questions and two answers:

Question 1:

A quadratic equation is shown below: 3x^2 − 15x + 20 = 0 Part A: Describe the solution(s) to the equation by just determining the radicand. Show your work.

The negative value of the radicand means that the equation does not have real solutions.

Explanation:

1) With radicand the statement means the disciminant of the quadratic function.

2) The discriminant is: b² - 4ac, where a, b, and c are the coefficients of the quadratic equation: ax² + bx + c

3) Then, for 3x² - 15x + 20, a = 3, b = - 15, and c = 20

and the discriminant (radicand) is: (-15)² - 4(3)(20) = 225 - 240 = - 15.

4) The negative value of the radicand means that the equation does not have real solutions.

Question 2:

Part B: Solve 3x^2 + 5x − 8 = 0 by using an appropriate method. Show the steps of your work, and explain why you chose the method used.

two solutions x = 1 and x = - 8/3x

Explanation:

1) I choose factoring (you may use the quadratic formula if you prefer)

2) Factoring

Given: 3x² + 5x − 8 = 0

Make 5x = 8x - 3x: 3x² + 8x - 3x - 8 = 0

Group: (3x² - 3x) + (8x - 8) = 0

Common factors for each group: 3x(x -1) + 8(x - 1) = 0

Coomon factor x - 1: (x - 1) (3x + 8) = 0

The two solutions are for each factor equal to zero:

x - 1 = 0 ⇒ x = 1

3x + 8 = 0 ⇒ x = -8/3

Those are the two solutions. x = 1 and x = - 8/3

a

step-by-step explanation:

hello from mrbilldoesmath!

answer:

(7 x + 6 y) (49 x^2 - 42 x y + 36 y^2)

discussion:

the trick is to recognize that 343 = 7^3 and 216 = 6^3 and, in general,

a^3 + b^3 =   (a + b) (a^2 - a b + b^2).

in our case

343x^3+216y^3   =   (7x)^3 + (6y)^3

so take a = 7x and b = 6y in the above equation to get the answer.

you,

mrb