GMAT Math Practice Test #1

Answer B

It is simply putting values with due care of positive and negative sign

y⁴+x³+y²+x= 1⁴+(-1)³+(1)²+(-1) = 1 -1+1-1 =0

Key takeaway: Remember simple rules of multiplication of positives (+) and negative (-) numbers. When you raise (-1) by an odd number you get negative sign and when you raise (-1) by an even number you get positive sign

(-1) = -1 (-1)² = +1 (-1)³ = -1