20. a.Solve for xfirst. Since 3x + 1= 81, and 81 is 34, make an easier equation just based on the exponents.This would be x+ 1 = 4.x= 3. Therefore,x– 1 = 3 – 1 = 2.

A.SOLVE FOR XFIRST. SINCE 3X + 1= 81, AND 81 IS 34, MAKE AN EASIER...

GMAT EXAM SUCCESS EPISODE 2 PART 11 PPS

20. a.Solve for xfirst. Since 3

^{x + 1}

= 81, and 81 is 3

⁴

, make an easier equation just based on the exponents.This would be x+ 1 = 4.x= 3. Therefore,x– 1 = 3 – 1 = 2.