Ariana is a citizen scientist for a monarch butterfly project. Every week, she visits a local patch of milkweed and counts the number of monarch larvae on the plants. Last week, Ariana didn't count many larvae. This week, she counts $19$ larvae on the milkweed. For both weeks, Ariana's total count is $26$ larvae. $\newline$ Which equation can you use to find the number of larvae $n$ Ariana counted last week? $\newline$ Choices: $\newline$ $(A)$ $\frac{n}{19} = 26$ $\newline$ $(B)$ $n + 19 = 26$ $\newline$ $(C)$ $n - 19 = 26$ $\newline$ $(D)$ $26$ $0$ $\newline$ Solve this equation for $n$ to find the number of larvae Ariana counted last week. $\newline$ $26$ $2$ larvae $\newline$

View step-by-step help

Home

Math Problems

Algebra 1

Solve one-step and two-step linear equations: word problems

Full solution

Q. Ariana is a citizen scientist for a monarch butterfly project. Every week, she visits a local patch of milkweed and counts the number of monarch larvae on the plants. Last week, Ariana didn't count many larvae. This week, she counts

19

larvae on the milkweed. For both weeks, Ariana's total count is

26

larvae.

\newline

Which equation can you use to find the number of larvae

n

Ariana counted last week?

\newline

Choices:

\newline

(A)

\frac{n}{19} = 26

\newline

(B)

n + 19 = 26

\newline

(C)

n - 19 = 26

\newline

(D)

26

0

\newline

Solve this equation for

n

to find the number of larvae Ariana counted last week.

\newline

26

2

larvae

\newline

Set Up Equation: To find the number of larvae Ariana counted last week, we need to set up an equation that relates last week's count $n$ and this week's count $19$ to the total count for both weeks $26$ . The correct equation should allow us to solve for $n$ , the number of larvae counted last week.
Eliminate Incorrect Choices: Looking at the choices, we can eliminate (A) because dividing $n$ by $19$ does not make sense in this context. We can also eliminate (C) because subtracting $19$ from $n$ suggests that this week's count would be subtracted from last week's count, which is not the case. Choice (D) is incorrect because multiplying $19$ by $n$ implies that the count for both weeks is the same, which is not given in the problem. The correct choice is (B) $n + 19 = 26$ because it represents adding this week's count ( $19$ ) to last week's count ( $n$ ) to get the total count ( $26$ ).
Solve Equation: Now we solve the equation from choice (B): $n + 19 = 26$ . To isolate $n$ , we need to subtract $19$ from both sides of the equation. $n + 19 - 19 = 26 - 19$ $n = 7$