问题


There is a single choice question about high school mathematics. Answer the question by replying A, B, C or D.
Question: Given the expression: $1990\times1991 - 1989\times1990$. What counting number is equivalent to the expression?
A. 5
B. 8
C. 3980
D. 1160
Answer:

答案

模型 模型答案 正确答案
金声玉亮2.0

C. 3980
C
deepseekr1

The expression can be simplified by factoring out the common term 1990:

\[
1990 \times 1991 - 1989 \times 1990 = 1990 \times (1991 - 1989).
\]

Calculating the difference inside the parentheses: \(1991 - 1989 = 2\). Thus, the expression becomes:

\[
1990 \times 2 = 3980.
\]

The correct answer is **C. 3980**.

**Answer:** C
C
gpto1 C C
GPT-4o To solve the expression \(1990 \times 1991 - 1989 \times 1990\), we can factor out the common term \(1990\):

\[
1990 \times 1991 - 1989 \times 1990 = 1990 \times (1991 - 1989)
\]

Next, we simplify inside the parentheses:

\[
1991 - 1989 = 2
\]

So the expression becomes:

\[
1990 \times 2 = 3980
\]

Thus, the counting number equivalent to the expression is:

C. 3980
C
llama3.1-70B-Instruct

C
C
llama3.1-405B-Instruct

C. 3980
C
DeepSeek-Coder-V2 A. 5 C
Qwen2-72B-Instruct C. 3980 C
baichuan4 B C
doubao C

$1990\times1991-1989\times1990=1990\times(1991-1989)=1990\times2=3980$.
C
minimax To solve the expression $1990\times1991 - 1989\times1990$, we can factor out the common factor of 1990:

$1990\times1991 - 1989\times1990 = 1990(1991 - 1989)$

Now, subtracting within the parentheses:

$1991 - 1989 = 2$

So the expression simplifies to:

$1990 \times 2$

Which is:

$3980$

Therefore, the correct answer is:

C. 3980
C
kimi To solve this problem, we can simplify the given expression step by step:

\[ 1990 \times 1991 - 1989 \times 1990 \]

We can factor out the common term, which is \( 1990 \):

\[ 1990 \times (1991 - 1989) \]

Now, we calculate the difference inside the parentheses:

\[ 1991 - 1989 = 2 \]

So the expression simplifies to:

\[ 1990 \times 2 \]

Now, we multiply:

\[ 1990 \times 2 = 3980 \]

Therefore, the correct answer is:

C. 3980
C
wenxinyiyan C
Explanation:
Begin by recognizing that the expression involves two products that share a common factor of 1990. We can rewrite the expression to group this common factor:
$1990\times1991 - 1989\times1990 = 1990\times(1991 - 1989)$
Then, simplify the difference inside the parentheses:
$1991 - 1989 = 2$
Finally, multiply this result by the common factor:
$1990\times2 = 3980$
The expression is equivalent to the counting number 3980, so the correct answer is C.
C
zhipu To solve the expression \( 1990 \times 1991 - 1989 \times 1990 \), we can use the distributive property of multiplication over subtraction.

First, factor out the common term \( 1990 \):
\[
1990 \times 1991 - 1989 \times 1990 = 1990 (1991 - 1989)
\]

Now, simplify the expression inside the parentheses:
\[
1991 - 1989 = 2
\]

So, the expression becomes:
\[
1990 \times 2 = 3980
\]

Therefore, the counting number equivalent to the given expression is 3980.

The correct answer is:
C. 3980
C
gpto1 C C
deepseekv3 To solve the expression \( 1990 \times 1991 - 1989 \times 1990 \), we can factor out \( 1990 \) from both terms:

\[
1990 \times 1991 - 1989 \times 1990 = 1990 \times (1991 - 1989)
\]

Next, simplify the expression inside the parentheses:

\[
1991 - 1989 = 2
\]

Now, multiply by \( 1990 \):

\[
1990 \times 2 = 3980
\]

Therefore, the expression is equivalent to \( 3980 \).

The correct answer is:

\boxed{C}
C