Solve Expression a·b+1 When a=2 and b=-2: Step-by-Step

Algebraic Substitution with Negative Numbers

a⋅b+1= a\cdot b+1=

Replace and calculate if a=2,b=−2 a=2,b=-2

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Place and calculate
00:04 Let's substitute appropriate values according to the given data, being careful with parentheses
00:19 Positive times negative is always negative
00:23 Let's continue solving according to the correct order of operations
00:27 And this is the solution to the question

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

a⋅b+1= a\cdot b+1=

Replace and calculate if a=2,b=−2 a=2,b=-2

2

Step-by-step solution

Let's begin by inserting the given data into the formula:

2×(−2)+1= 2\times(-2)+1=

Remembering the rule:

(+x)×(−x)=−x (+x)\times(-x)=-x

Let's now solve the multiplication operation:

2×(−2)=−4 2\times(-2)=-4

In order to obtain the following expression:

−4+1= -4+1=

Therefore, the answer is:

−3 -3

3

Final Answer

−3 -3

Key Points to Remember

Essential concepts to master this topic
  • Substitution: Replace variables with given values: a=2, b=-2
  • Multiplication: Positive times negative equals negative: 2×(-2)=-4
  • Check: Verify order of operations: multiply first, then add ✓

Common Mistakes

Avoid these frequent errors
  • Adding before multiplying
    Don't calculate a+1 first, then multiply by b = wrong order! This ignores order of operations and gives incorrect results. Always multiply a·b first, then add 1.

Practice Quiz

Test your knowledge with interactive questions

a is negative number.

b is negative number.

What is the sum of a+b?

FAQ

Everything you need to know about this question

Why is 2×(-2) equal to -4 and not +4?

+

When you multiply a positive number by a negative number, the result is always negative. Think of it as: positive × negative = negative. So 2×(−2)=−4 2 \times (-2) = -4 .

Do I need to use parentheses when substituting negative values?

+

Yes! Always put parentheses around negative values when substituting: 2×(−2) 2 \times (-2) . This prevents confusion and helps you apply the correct multiplication rules.

What if I accidentally did the addition first?

+

If you calculated 2×(−2+1)=2×(−1)=−2 2 \times (-2+1) = 2 \times (-1) = -2 , you'd get the wrong answer! Remember: multiplication comes before addition in order of operations (PEMDAS).

How can I remember the sign rules for multiplication?

+
  • Same signs: positive × positive = positive, negative × negative = positive
  • Different signs: positive × negative = negative, negative × positive = negative

Should I double-check my final calculation?

+

Absolutely! Substitute back: a⋅b+1=2×(−2)+1=−4+1=−3 a \cdot b + 1 = 2 \times (-2) + 1 = -4 + 1 = -3 . This confirms our answer is correct.

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Algebraic Expressions questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations

Multiplication and Division of Signed Mumbers

Solve b(a+4): Substituting Values a=-6 and b=-2
Click to solve
Solve the Expression: a + b(a+1) with a=2 and b=-3
Click to solve

The Domain of an Algebraic Expression

Solve a·b+b: Substituting Values a=-3 and b=-2
Click to solve
Solve a(ab+3): Evaluating the Expression When a=-1 and b=5
Click to solve