3. Task 2.2 № 9856: Calculate (-7.5 + 1.7) * 2.9

First, calculate the expression inside the parentheses: $$-7.5 + 1.7 = -5.8$$ Next, multiply the result by 2.9: $$-5.8 * 2.9 = -16.82$$ So, the answer is **-16.82**.