Answer:
His age is 7 years.
Step-by-step explanation:
Let Rehman's present age be x years.
1 / (x - 3) + 1 /(x + 5) = 1/3
Multiply through by the LCD 3(x - 3)(x + 5):
3(x + 5) + 3(x - 3) = (x + 5)(x - 3)
3x + 15 + 3x - 9 = x^2 + 2x - 15
x^2 + 2x - 6x - 30 + 9 = 0
x^2 - 4x - 21 = 0
(x - 7)(x + 3) = 0
x = 7 (answer).
Substitute the first equation into the second equation. You will get:
4x - (2x - 5) = 7
Distribute the negative sign into the parenthesis:
4x - 2x + 5 = 7
Simplify
2x + 5 = 7
Subtract 5 on both sides
2x = 2
x = 1
Now, substitute x = 1 into the first equation:
y = 2(1) - 5
y = 2 - 5
y = -3
The solution to the system of equations is (1, -3).
Answer:
The number of nickel coins is 10 and the number of quarter coins is 5
Step-by-step explanation:
<u><em>The correct question is</em></u>
Mary has 15 coins with the total value of $1.75 if the coins are nickels and quarters how many of each kind are there
Let
x ----> the number of nickel coins
y ----> the number of quarter coins
Remember that
we know that
Mary has 15 coins
so
-----> equation A
The total value of the coins is $1.75
so
----> equation B
Solve the system by graphing
Remember that the solution is the intersection point both graphs
using a graphing tool
The solution is the point (10,5)
therefore
The number of nickel coins is 10 and the number of quarter coins is 5