Soru

Zorluk: Çok zorLinear Equations in One and Two Variables

A financial analyst models a company's total annual revenue, R(t)R(t), and total annual expenses, E(t)E(t), in thousands of dollars, as linear functions of time tt, where tt represents the number of years since 2020. In 2022 (t=2t = 2), the annual revenue was $850,000\$850,000 and annual expenses were $610,000\$610,000. In 2025 (t=5t = 5), the annual revenue reached $1,120,000\$1,120,000 while annual expenses reached $700,000\$700,000. Assuming these linear trends continue, in which calendar year will the company's annual profit (defined as total annual revenue minus total annual expenses) reach exactly $540,000\$540,000?

Cevap: 2027

Cevap

The company's annual profit will reach $540,000 in the year 2027.
The linear profit function increases at a constant rate of 60,000peryearfromabaseprofitof60,000 per year from a base profit of 240,000 in 2022 (t=2t = 2). Solving 240+60(t2)=540240 + 60(t - 2) = 540 yields t=7t = 7, which corresponds to the calendar year 2027.

Adım Adım Çözüm

1
Calculate the annual profit in thousands of dollars for the known years 2022 (t=2t = 2) and 2025 (t=5t = 5).
In 2022 (t=2t = 2), profit P(2)=850610=240P(2) = 850 - 610 = 240 thousand dollars. In 2025 (t=5t = 5), profit P(5)=1120700=420P(5) = 1120 - 700 = 420 thousand dollars.
Profit is defined as revenue minus expenses.
2
Determine the linear profit function P(t)=mt+bP(t) = mt + b.
The rate of change of profit per year is m=42024052=1803=60m = \frac{420 - 240}{5 - 2} = \frac{180}{3} = 60 thousand dollars per year.
Since both revenue and expenses are linear functions of time tt, their difference P(t)=R(t)E(t)P(t) = R(t) - E(t) is also a linear function of tt.
3
Set up the linear equation for profit using point-slope form.
P(t)240=60(t2)    P(t)=60t+120P(t) - 240 = 60(t - 2) \implies P(t) = 60t + 120.
Using the point (2,240)(2, 240) and slope m=60m = 60 establishes the complete linear equation for annual profit.
4
Solve the linear equation for tt when profit P(t)=540P(t) = 540 thousand dollars.
60t+120=540    60t=420    t=760t + 120 = 540 \implies 60t = 420 \implies t = 7.
Setting the profit equal to 540 gives the value of tt years after 2020.
5
Convert the value of tt into the target calendar year.
Calendar Year =2020+7=2027= 2020 + 7 = 2027.
Since tt represents years elapsed since 2020, t=7t = 7 corresponds to calendar year 2027.

Anahtar Kavram

Linear Modeling and Linear Equations in Two Variables
Bu soruyu puanla