Doroshana, Hemant, and Rupesh got different answers for this problem:
1 - 10 - 3{-10 + 2} - 4
Doroshana's answer was 1, Hemant's answer was -29, and Rupesh's answer was 21.
Which student had the correct answer?
Show and explain how the other two students got their answers. What errors did they make?
Answer (1)
To solve the given mathematical expression and determine which student provided the correct answer, let's break it down step-by-step.
The expression given is:
1 − 10 − 3 { − 10 + 2 } − 4
Start with the innermost bracket: − 10 + 2 = − 8
Substitute back into the expression: 1 − 10 − 3 ( − 8 ) − 4
Multiply: 3 ( − 8 ) = − 24
Substitute back into the expression: 1 − 10 + 24 − 4
Calculate step by step from left to right:
1 − 10 = − 9
− 9 + 24 = 15
15 − 4 = 11
Therefore, the correct answer is 11 , suggesting all three students provided incorrect answers.
Let's examine how each student may have arrived at their answers:
Doroshana's Answer (1): It's possible Doroshana made an error in applying the multiplication or combining the steps improperly. They might have ignored or miscalculated the effects of negative numbers or the multiplication step.
Hemant's Answer (-29): Hemant likely miscalculated at the multiplication or subtraction step. He might have incorrectly added or failed to convert a minus into a plus for multiplication effects.
Rupesh's Answer (21): Rupesh possibly missed a negative sign somewhere, especially during subtraction, and added numbers erroneously.
To recap, none of Doroshana, Hemant, or Rupesh had the correct answer. The accurate and correctly calculated result is 11.
