Answer:
The solutions of the original equation are x=-5 and x=-2
Step-by-step explanation:
we have

Let

Rewrite the equation

Complete the square



rewrite as perfect squares

square root both sides




the solutions are
u=-2,u=1
<em>Alternative Method</em>
The formula to solve a quadratic equation of the form
is equal to
in this problem we have

so
substitute in the formula
the solutions are
u=-2,u=1
<em>Find the solutions of the original equation</em>
For u=-2
----> 
For u=1
----> 
therefore
The solutions of the original equation are
x=-5 and x=-2
Let the marks of Devi be x and Ali be y.
So, the equations:
2y = x <em>and</em> y + 16 = x
So,
2y = y + 16. [ because we know equals are equal to equals]
=> 2y - y = 16
=> y = 16
Check
Ali's marks are half of Devi's marks.
Devi's marks are 16 more than alis.
So, Devi's marks will be 16×2 = 32 and 32 is 16 greater than 16 (16+16=32).
7-3=4
9-2=7
4x7=28
Use PEMDAS for order of operations, it will save your life
Parenthesis Exponents Multiply Divide Add Subtract
Multiply and Divide and Add and Subtract can be switched around with each other, but multiply and divide always happens before add and subtract. The reason you add first here is because it is in the parenthesis.