By definition, a rational number is a precise number: or in other terms, we know its exact value. Irrational numbers are number that has endless digits on the right of the decimal points: in other terms, we can't know its exact value.
First question:
√2.5 = 1.58113.... It's endless, so irrational.
-√64 = -8 it's a whole number, so rational.
4√5 = 8.94427.... Endless, so irrational.
√14.4 = 3.7947... Endless so irrational.
So -√64 is the rational number.
Second:
7.885 is rational because has a defined number of digits after the decimal points.
π² = 9.8696.... Endless, so irrational.
√0.144 = 0.3794.... Endless, so irrational
√91 = 9.5393.... Endless, so irrational
So 7.885 is the rational number.
Third:
-7.8 bar: You can notice the line over the 8, this means that there's an infinite number of 8 after the decimal points. So it's 7.88888888888.... Endless, so irrational.
√25 = 5, whole number so rational
25.8125 Has a definite number of digits after the decimal point, so is rational.
√0.025 = 0.1581... Endless, so irrational.
So -7.8 bar and √0.025 are irrational.
Fourth:
π= 3.1415... Endless, so irrational.
1.425 has a definite number of digits after the decimal point, so rational.
√50 = 7.0710.... Endless, so irrational
√-4 Doesn't exist. Finding the square root of a negative number is mathematically impossible.
So 1.425 is the rational number.
Fifth:
√10 = 3.1622..... Endless, so irrational.
√100 = 10, a whole number so rational.
√1000 = 31.6227..... Endless, so irrational
√100000 = 316.2277...... Endless, so irrational.
√100 is the rational number.
Hope this helps!! :D And I hope you understood the lesson a bit more xD
Answer:
Let cost of one bag be Y
8 x Y = $20
So, Y = $2.5
Now cost of 3 bags = 3 x 2.5 = $7.5
Answer: 21
Step-by-step explanation:
56/8= 7
7*3= 21
Slope of y=1-2x is -2
Using point intercept form:
y-1=-2(x-3)
y-1=-2x+6
y=-2x+7
No, (2,2) is not solution of y < 4x - 6
Step-by-step explanation:
To solve above linear problem, we use standard method of Back- Substitution.
First of all, A point (2,2) only becomes solution of equation, if it satisfies equation 
.
Here, the seems to be like a linear equation.
In this Equation, using Back- Substitution method,
Point (2,2) : first digit 2 corresponds to x- coordinate and second digit 2 corresponds to y-coordinate.
By putting value of x and y in equation (1),
Equation becomes,
.... not true mathematically.
Finally, the result came is not true. Therefore, (2,2) is not solution for equation
