The sum of their ages equals 80.
Gabrielle is 3 times older than Mikhail
Two numbers that have a sum of 80, with one number being 3 times the other are:
Gabrielle’s age: 60
Mikhail’s age: 20
60 + 20 = 80
20 x 3 = 60
Mikhail is 20 years old.
Your question is:

Then, the above formula equate:

Factor out 8 from the numerator we get:

Factorization of the denominator:

Simplifying the numerator and the denominator by (u-9) we get:
Answer:
3x - 300
Step-by-step explanation:
Expand the brackets or use distribute law.
Answer:
81
Step-by-step explanation:
Let the digits that make up the number be a and b.
Given that the square root of the number is equal to the sum of the digits.
Then,
√(10a + b) = a + b
Also given that the square root of the number is less than the number obtained by interchanging the digits by 9, then
√(10a +b) + 9 = 10b + a
Since √(10a + b) = a + b, then
a + b + 9 = 10b + a
a - a + 9 = 10b - b
9b = 9
b = 1
since √(10a + b) = a + b
√(10a + 1) = a + 1
10a + 1= (a + 1)²
10a + 1 = a² + 2a + 1
a² + 2a - 10a + 1 - 1 = 0
a² - 8a = 0
a(a - 8) = 0
a = 0 or a = 8
Using a = 8 and b = 1,
the number 10a + b = 10(8) + 1 = 81.
Answer:
Total number of tables of first type = 23.
Total number of tables of second type = 7
Step-by-step explanation:
It is given that there are 30 tables in total and there are two types of tables.
Let's call the two seat tables, the first type as x and the second type as y.
∴ x + y = 30 ......(1)
Also a total number of 81 people are seated. Therefore, 2x number of people would be seated on the the first type and 5y on the second type. Hence the equation becomes:
2x + 5y = 81 .....(2)
To solve (1) & (2) Multiply (1) by 2 and subtract, we get:
y = 7
Substituting y = 7 in (1), we get x = 23.
∴ The number of tables of first kind = 23
The number of tables of second kind = 7