Roxy used a calculator to evaluate (18 + 2) × (49 – 34) – 63 ÷ 9 by entering c 18 + 2 * 15 – 7 into a calculator. which statement is true?
the calculator will show the correct value because 2 should be multiplied by 15 first.
the calculator will show the correct value because 7 should be subtracted from 18 first.
the calculator will show an incorrect value. she should have added 18 and 2 and then entered c 20 * 15 – 7 into the calculator.
the calculator will show an incorrect value. she should have subtracted 7 from 15 and then entered c 18 + 2 * 8 into the calculator.

  The calculator will show an incorrect value. She should have added 18 and 2 and then entered C 20 * 15 – 7 into the calculator.

Step-by-step explanation:

Some calculators will properly evaluate the expression entered as shown:

  (18+2)×(49-34)-63÷9

  = 20×15 -7

  = 293

Others require careful entry of the numbers with an awareness of how the calculator uses them.*

Apparently, Roxy's calculator requires a certain amount of "care and feeding," meaning that she has to partially evaluate the expression before using the calculator.

* My personal preference is for an RPN calculator, which always executes the function you tell it on the numbers you can see. (It has no parentheses.) To do Roxy's calculation, the entry on my calculator is ...

  18 2 + 49 34 – × 63 9 ÷ – . . . . . . the result is 293

Some "algebraic" calculators will do the operations in the order entered. That is, they maintain no "pending" operations. (I recommend against getting one of these.) Others have a limit on the number of "pending" operations they can accommodate. You need to know how your calculator handles deeply nested parentheses before you rely on it for complicated calculations.

the thermometer is precise but not accurate

step-by-step explanation: