15m + 2n, first you have to pair the matching variables, 8m and 7m along with the sign in front of them. so 8m(+7m), you would then add those then do the same with the other, +4n(postive) and -2n, so subtract 2 from 4 and get 2. put them together and it’s 15m+2
7/10 as hundredths= 70/100
7/10 as decimal form : 0.7 or .70 or .7
Start by adding 2 to both sides to get 3r^2 = 48. then divide both sides by 3 to get r^2 = 16. square root both sides to get r = 4.