According to the distributive property, a factor outside parentheses multiplies each term inside parentheses. The product of two negative numbers is positive, so you have ...
No. The amounts of change are the same, but the original amounts are different. The ratio for the percent increase from 50 to 70 is 20/50, or 40%. The ratio for the percent decrease from 70 to 50 is 20/70, or about 29%.