Match the solution set given in inequality notation with the solution set given in interval notation. xs 7.8
(7.8,00)
x < 7.8
(-0, 7.8)
x 27.8
[7.8,00)
x > 7.8
(-0, 7.8]

x≤7.8  ⇒(-∞;7.8]

x<7.8  ⇒ (-∞;7.8)

x>7.8  ⇒ (7.8; ∞)

x≥7.8  ⇒ [7.8; ∞)

Step-by-step explanation:

Hi, to answer this question we have to analyze each expression:

• x≤7.8

The solution is all the numbers less or equal to 7.8, since it can be equal to 7.8, it includes 7.8 , we have to use closed brackets

(-∞;7.8]

• x<7.8

All the numbers less than 7.8 , it excludes the endpoint , it's an open interval (parenthesis)

(-∞;7.8)

• x>7.8

All the numbers higher than 7.8, open interval (parenthesis)

(7.8; ∞)

• x≥7.8

All the numbers higher or equal to 7.8, closed interval (closed brackets for the endpoint)

[7.8; ∞)

answer: standard form is ax^2 + bx + c = 0

step-by-step explanation:

standard form is ax^2 + bx + c = 0

(2x + 1)(x - 2) = 0

distribute to get into standard form

2x^2 - 4x + x - 2 = 0

2x^2 - 3x - 2 = 0

a = 2, b= -3, c = -2

a is your answer

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so: