Eric was rock climbing. At one point, he stopped and climbed straight down 221 meters. Then he climbed straight up 643 meters. Eric was wondering what his change in elevation was after these two moves.Which of the following equations matches the situation above?Choose 1 answer:(A) −221−643= ?(B) 221−643= ?(C) −221+643= ?
Q. Eric was rock climbing. At one point, he stopped and climbed straight down 221 meters. Then he climbed straight up 643 meters. Eric was wondering what his change in elevation was after these two moves.Which of the following equations matches the situation above?Choose 1 answer:(A) −221−643= ?(B) 221−643= ?(C) −221+643= ?
Climb Down: Eric first climbed down, which means his elevation decreased. Climbing down 221 meters can be represented as a negative change in elevation. Therefore, we write this as −221 meters.
Climb Up: Next, Eric climbed up, which means his elevation increased. Climbing up 6(43) meters is a positive change in elevation. We represent this as +6(43) meters.
Combine Changes: To find the total change in elevation, we need to combine these two changes. Since climbing down is a negative change and climbing up is a positive change, we add the two values together, taking into account their signs. The equation that matches the situation is −2(21)+6(43)=?.
Convert to Fractions: Now we need to perform the calculation. First, we convert the mixed numbers to improper fractions to make the calculation easier. 221=22×2+1=25643=46×4+3=427The equation now looks like this: −25+427=?.
Add Fractions: We need a common denominator to add these fractions. The common denominator for 2 and 4 is 4. We convert −25 to a fraction with a denominator of 4 by multiplying both the numerator and the denominator by 2. This gives us −410. The equation now looks like this: −410+427=?.
Convert to Mixed Number: Now we can add the fractions since they have the same denominator. −410+427=427−10=417.
Convert to Mixed Number: Now we can add the fractions since they have the same denominator. −410+427=4(27−10)=417.Finally, we can convert the improper fraction back to a mixed number to find Eric's change in elevation. 417=4(41) or 4.25 meters.So, Eric's change in elevation is 4(41) meters.
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