In 16years, ben will be 3 times as old as he is right now.
how old is he right now?

8 years old is he right now.

Step-by-step explanation:

Let the present age of Ben be x.

As per the statement:

After 16 years.

Age of Ben will be = x + 16

In 16 years, Ben will be 3 times as old as he is right now.

⇒

Subtract x from both sides we have;

Divide both sides by 2 we have;

8 = x

or

x = 8 years

Therefore, 8 years old is he right now.

the answer is  

a.

4,624π mm2

step-by-step explanation:

option (a)

step-by-step explanation:

step 1:   take 2 number whose product equal to 25..

and sum of those two number are -10

step: 2 for example here if we take 5,5 are the number,,

5*5=25

and

5+5=10

but we need -10

so if we take   -5,-5

so -5*-5=25

and -5+(-5)=-10

s0

come the equation

replace -10x by these number

like -5x -5x+25

take common

x(x-5)-5(x-5)=0

(x-5)(x-5)=0