at present Ankit is twice as old as his son in four years he will be four times as old as what his son was 9 years ago find the present years of both of them

His son present age is 20 years

His present age is 40 years

Step-by-step explanation:

Assume that this son's age now is x years

∵ His son's age now = x years

∵ Ankit age is twice as old as his son

→ Twice means × 2

∴ Ankit age = 2 × x = 2x years

→ In for years means after 4 years (add)

∵ His age in four years = 2x + 4

→ 9 years ago means before 9 years (subtract)

∵ His son 9 years ago = x - 9

∵ In 4 years he will be four times as old as what his son was 9 years ago

→ That means 2x + 4 = 4 × (x - 9)

∴ 2x + 4 = 4(x - 9)

→ Let us solve the equation to find x

∴ 2x + 4 = 4(x) - 4(9)

∴ 2x + 4 = 4x - 36

→ Subtract 4 from both sides

∵ 2x + 4 - 4 = 4x - 36 - 4

∴ 2x = 4x - 40

→ Subtract 4x from both sides

∵ 2x - 4x = 4x - 4x - 40

∴ -2x = -40

→ Divide both sides by -2

∵ =

∴ x = 20

∵ x represents the present age of his son

∴ His son present age is 20 years

∵ 2x represents his present age

∵ 2(20) = 40

∴ His present age is 40 years

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.

49%

step-by-step explanation:

when you realize that you dont know just realize i just took a test and im so smart