What is the answer to 11x+9-16x= -21

11x+9-16x=-21

Simplify both sides of the equation

11x+9-16x=-21

Combine like terms

(11x+-16x)+(9)=-21

-5x+9=-21

Subtract 9 from both sides

-5x+9-9=-21-9

-5x=-30

Divide both sides by -5

-5x/-5=-30/5

x=6 

I hope that's help !

answer: it's upside down and i can't read it

step-by-step explanation:

answer: 8 years

step-by-step explanation:

the explanation is that in 8 years the child will be 20 and in 8 years the father will be 40 and 20 is half of 40.