Answer:
D. We can label the rational numbers with strings from the set (1, 2, 3, 4, 5, 6, 7, 8, 9, / -) by writing down the string that represents that rational number in its simplest form. As the labels are unique, it follows that the set of rational numbers is countable.
Step-by-step explanation:
The label numbers are rational if they are integers. The whole number subset is rational which is written by the string. The sets of numbers are represented in its simplest forms. The rational numbers then forms numbers sets which are countable.
Answer:
(- 3, 37) and (-
,
)
Step-by-step explanation:
Given the 2 equations
2x² - y + 19 = 0 → (1)
y + 11x = 4 → (2) ← subtract 11x from both sides
y = 4 - 11x → (3)
Substitute y = 4 - 11x into (1)
2x² - (4 - 11x) + 19 = 0
2x² - 4 + 11x + 19 = 0
2x² + 11x + 15 = 0 ← in standard form
(2x + 5)(x + 3) = 0 ← in factored form
Equate each factor to zero and solve for x
2x + 5 = 0 ⇒ 2x = - 5 ⇒ x = - 
x + 3 = 0 ⇒ x = - 3
Substitute these values into (3) for corresponding values of y
x = -
: y = 4 +
=
⇒ (-
,
)
x = - 3 : y = 4 + 33 = 37 ⇒ (- 3, 37 )
Answer:
It's already a rational number?
Step-by-step explanation:
A rational number is any number that can be written as a fraction/ratio, and
is certainly a fraction. If you meant
as a decimal, then it'd be 2.625.
7th grade: 62/120 of the class is made up of girls; (120-62)/120 of boys.
8th grade: 58/120 of the class is made up of boys; (120-58)/120 of girls.
Looking at the info for boys only: Compare (120-62)/120 with 58/120. What do you see?
Answer:
<h2>140 minutes</h2>
Step-by-step explanation:
this problem focuses on the combined work rate
both can finish the work under 63 minute
let bobby mow the lawn in x minute
Billy will then mow the lawn in x-25 minutes
Let the completed job = 1 (a mowed lawn)
we can now apply the combined work formula for the two boys as
multiplying through by x(x-25 )we have

open bracket we have

rearranging and collecting like terms we have

we can now use the quadractic formula
a= 1
b= -151
c= 1575



the first answer x= 139.72 approximately 140 minutes mins is correct for Bobby's time
let us check

we can see that the solution approximates to 1