Answer:
<em>In 5 years the product of their ages will be 208</em>
Step-by-step explanation:
The age of two children is 11 and 8 years.
Let's call x the number of years ahead.
We need to find when the product of their future ages is 208. The 11 years old child will be 11+x years old and the other child will be 8+x years, thus:
(11+x)(8+x)=208
Operating:
Simplifying:
Factoring:
(x-5)(x+24)=0
Solving:
x=5, x=-24
The negative solution is not valid, thus x=5
In 5 years the product of their ages will be 208
Answer:
x = 6
Step-by-step explanation:
Find the equation of the line
y = mx + b
Use the slope given 3 and the x of 4 and the y of 11 from the point given (4,11)
11 = 3(4) +b Solve for y
11 = 12 + b Subtract 12 from both sides
-1 = b
y = 3x -1 This is the equation of the line. Substitute in 17 for y and solve for x
17 = 3x -1 Add 1 to both sides
18 = 3x Divide both sides by 3
6 = x
Let the three apartments be A, B & C
The rent of A is $x
The rent of B is $y
The rent of C is $z
So x + y + z = 1600 .......(1)
Now
Maintenance of A is 20% of x = 0.20x
Maintenance of B is 20% of y = 0.20y
Maintenance of C is 25% of z = 0.25z
0.20x + 0.20y + 0.25z = 345
Multiplying by 100 we get
20x + 20y + 25 z = 34500
Dividing by 5 we get
4x + 4y + 5z = 6900 .......(2)
Monthly fee of A is 10% of x = 0.10x
Monthly fee of B is 20% of y = 0.20 y
Monthly Fee of C is 10% of z = 0.10z
Now
0.10x + 0.20y + 0.10 z= 1820 - 1600
0.10x + 0.20y + 0.10z = 220
Multiplying by 100 we get
10x + 20y + 10z = 22000
Dividing by 10
x + 2y + z = 2200 ....(3)
Making a Matrix of equation (1), (2) & (3)
![\left[\begin{array}{ccc}1&1&1\\4&4&5\\1&2&1\end{array}\right] \left[\begin{array}{c}x\\y\\z\end{array}\right] =\left[\begin{array}{c}1600\\6900\\2200\end{array}\right]](https://tex.z-dn.net/?f=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%261%261%5C%5C4%264%265%5C%5C1%262%261%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7Dx%5C%5Cy%5C%5Cz%5Cend%7Barray%7D%5Cright%5D%20%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bc%7D1600%5C%5C6900%5C%5C2200%5Cend%7Barray%7D%5Cright%5D%20%20%20)
is the required matrix
The first answer is -45 but I don't know the other one's man.
