Respuesta :

hummm
Nobody understands maths and if you do you were sent from heaven

Answer:

r = 1

Step-by-step explanation:

first you have to expand the brackets.

3 x 7 = 21

3 x -2r = -6r

the equation is now 21-6r = 21r-6

now you simplify it so get the answer r = 1

Q&A Education