[99 pts] answer these questions . 1.if a = -9 and b = -4, what is the value of a + b ? -5 5 -13 13 2. simplify 2 x2 - y for x = 3 and y = -2. 20 14 16 10 3. the cost for children under twelve at a certain buffet restaurant is a base charge of a dollar plus twenty-five cents for each year of the child's age. represent this cost as an expression, using y to stand for the child's age in years. then use the expression to find the cost for a child who is nine. 1 + 0.25 y ; $2.25 1 + 0.25 y ; $3.25 0.25 + y ; $9.25 0.25 + y ; $8.75 4. tommy and his family drove home from his grandparent's house in three and a half hours. if they drove at an average rate of 48 miles per hour, which of the following formulas could be used to find how far away tommy lives from his grandparents? d = rt t = d/r r = d/t 5. tommy and his family drove home from his grandparent's house in three and a half hours. if they drove at an average rate of 48 miles per hour, about how far away does tommy live from his grandparents? 144 miles 192 miles 168 miles 180 miles 5. hillary opened a savings account with $1,500. how much simple interest will she earn if she leaves the money in the account for two years at an interest rate of 0.025? use the formula i = prt . $750.00 $37.50 $375.00 $75.00 6.convert 15°c to fahrenheit. use the formula f = c + 32. 59°f 27°f 85°f 33°f answer them !