Question

noam solved the equation for k using the following calculations.
k - 7.6 = 10.35
+7.6 +7.6
k = 17.41
what error, if any, did he make?
he should have subtracted 7.6 instead of adding it.
he should have subtracted 10.35 from both sides.
he made a computation error when he added 10.35 + 7.6.
he made a computation error when he added -7.6 and 7.6.

Explanation:

Step1: Analyze the equation

The original equation is \( k - 7.6=10.35 \). To solve for \( k \), we need to isolate \( k \). The correct operation is to add \( 7.6 \) to both sides of the equation, because the inverse operation of subtraction is addition. So the first two options are incorrect as they suggest wrong operations.

Step2: Check the addition

Now, let's check the addition \( 10.35 + 7.6 \).
\( 10.35+7.6 = 10.35+7.60=17.95 \), but Noam got \( 17.41 \). So he made a computation error when he added \( 10.35 + 7.6 \). The last option about adding \( - 7.6 \) and \( 7.6 \) is not relevant here because we are adding \( 7.6 \) to both sides, not dealing with \( -7.6+7.6 \) in the context of this addition for solving \( k \).

Answer:

He made a computation error when he added \( 10.35 + 7.6 \) (the option: He made a computation error when he added \( 10.35 + 7.6 \))