Answer:
Step-by-step explanation:
The sum of the ages of a Mother and her son is 78 , three years ago the mother is five times as old as the son, what is their present ages?
To solve this , let the age of the mother be x and the age of the son be y , from the first statement :
x + y = 78
Three years ago , the mother will be x- 3 and the son will be y - 3 , from the second statement:
x - 3 = 5 ( y-3)
x- 3 = 5y - 15
x - 5y = -12
The resulting equations are 
x + y = 78
x - 5y = -12
This is called a simultaneous linear equation , that means it is a linear equation.
The side of a square is xcm , if the difference between the area and the perimeter is 12 , find the legth of its side.
Interpretation:
The formula for the area of a square is  and the perimeter is 4l , from the question , we have
 and the perimeter is 4l , from the question , we have
 - 4x = 12
 - 4x = 12
This is not a linear equation , it is simply a quadratic equation , so the situation is non linear
 
        
             
        
        
        
Answer:
(x - 3)² + (y - 5)² = 16
Step-by-step explanation:
the equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k ) are the coordinates of the centre and r the radius
given (h, k ) = (3, 5 ) we require to find r
r is the distance from the centre to a point on the circle
given x = - 1 is a tangent the r is the distance between the x- coordinates
r = | 3 - (- 1) | = | 3 + 1 | = | 4 | = 4
then equation of circle is
(x - 3)² + (y - 5)² = 4² , that is
(x - 3)² + (y - 5)² = 16
 
        
             
        
        
        
Answer:
x=12
10x = 120
5x = 60
Step-by-step explanation:
paralellograms will become 360 degrees
so 2(5x) +2(10x)= 360
Simplify:
10x + 20x = 360
= 30x 
divide both sides by 30 and isolate
<u>30x </u> = <u>360</u>
30        30
x=12
multiply 12 by 10x and 5x
10x = 120
5x = 60
 
        
             
        
        
        
Answer:
-334
Step-by-step explanation:
tyes sfdfa d
 
        
             
        
        
        
Answer:
I Think the honor of total students is 50%
Step-by-step explanation:
25 +17=45
Round 45 to the nearest tenth and you get 50