Difference between revisions of "2021 Mock AMC 8 Problems/Problem 1"

Latest revision as of 15:05, 16 October 2021

What is the value of $1-2+3-4+5-6+7-8+9$ ?

$\mathrm{(A)}\ 4 \qquad\mathrm{(B)}\ 5 \qquad\mathrm{(C)}\ 6 \qquad\mathrm{(D)}\ 7 \qquad\mathrm{(E)}\ 25$

Since $1-2+3-4+5-6+7-8$ is $-4$ , so we have $-4 + 9 = 5$ Therefore, our answer is $\boxed{\textbf{(B) } 5} \qquad$

@@ Line 1: / Line 1: @@
-==Problem 1==
+==Problem==
 What is the value of <math>1-2+3-4+5-6+7-8+9</math>?
 <math>\mathrm{(A)}\ 4 \qquad\mathrm{(B)}\ 5 \qquad\mathrm{(C)}\ 6  \qquad\mathrm{(D)}\ 7 \qquad\mathrm{(E)}\ 25</math>
-==Solutions==
 ==Solution 1==
+Since <math>1-2+3-4+5-6+7-8</math> is <math>-4</math>, so we have <math>-4 + 9 = 5</math> Therefore, our answer is <math>\boxed{\textbf{(B) } 5} \qquad</math>