You do it by using your brain!!
-5 = 7 + 3r | subtract 7 -12 = 3r | divide by 3 -4 = r
5
3r-2 for r=65
2
It is simply 3r
If that's 3r + 12, that factors to 3(r + 4)
(3r + 2)(r - 5)
factor out the common monomial, 5. 5(r^3-1) Factor as a difference of cubes. 5(r-1)(r^2+r+1)
(3r - 2)(3r - 2) or (3r - 2) squared.
-5 = 7 + 3r | subtract 7 -12 = 3r | divide by 3 -4 = r
7 + r(3 - t)
17 = 13 - 3r Subtract 13 from bith sides: 4 = -3r Divide both sides by -3 : -4/3 = r or r = -1.3...
If: -5 = 7+3r then the value of r works out as -4
5
3r-r equals 12 = -9
3r/4
(3r - 8)(3r - 8)