Simplify the following:
(-20)/(-5) - (57 + 6)/(-9)
Reduce (-20)/(-5) to lowest terms. Start by finding the GCD of -20 and -5.
The gcd of -20 and -5 is -5, so (-20)/(-5) = (-5×4)/(-5×1) = (-5)/(-5)×4 = 4:
4 - (57 + 6)/(-9)
Evaluate 57 + 6 using long addition.
Reduce 63/(-9) to lowest terms. Start by finding the GCD of 63 and -9.
The gcd of 63 and -9 is 9, so 63/(-9) = (9×7)/(9 (-1)) = 9/9×7/(-1) = 7/(-1):
4 - 7/(-1)
Simplify the sign of 7/(-1).
Multiply the numerator and denominator of 7/(-1) by -1:
4 - -7
Multiply all instances of -1 in -(-7).
(-1)^2 = 1:
4 + 7
=11
