Make r the subject of the formula p=10 (q-3r) divided by r

(10q-p) / 30=r

Step-by-step explanation:

p=10 (q-3r)

distribute

p = 10*q - 10 * 3r

p = 10q - 30r

subtract 10q from each side

p-10q = 10q-10q-30r

p-10q = - 30r

divide by - 30

(p-10q) / -30 = - 30r/-30

- (p-10q) / 30 = r

distribute

(-p+10q) / 30 = r

i would rewrite to put the positive term 1st, put that is a personal choice (my negative get lost in the parenthesis)

(10q-p) / 30=r