Question

A bean plant grows at a constant rate for a month. After 10 days, the plant is 25 centimeters tall. After 20 days, the plant is 45 centimeters tall.Which equation models the height of the plant, y, after x days?
A.y – 10 = (x – 25)
B.y – 25 = (x – 10)
C.y + 25 = 2(x + 10)
D.y – 25 = 2(x – 10)

Answer 1

$\bf \begin{array}{ccllll} days(x)&cm(y)\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 10&25\\ 20&45 \end{array}\\\\ -------------------------------\\\\ \begin{array}{lllll} &x_1&y_1&x_2&y_2\\ % (a,b) &({{ 10}}\quad ,&{{ 25}})\quad % (c,d) &({{ 20}}\quad ,&{{ 45}}) \end{array}$

$\bf slope = {{ m}}= \cfrac{rise}{run} \implies \cfrac{{{ y_2}}-{{ y_1}}}{{{ x_2}}-{{ x_1}}}\implies \cfrac{45-25}{20-10}\implies \cfrac{20}{10}\implies 2 \\\\\\ % point-slope intercept y-{{ y_1}}={{ m}}(x-{{ x_1}})\implies y-25=2(x-10)\\ \left. \qquad \right. \uparrow\\ \textit{point-slope form}$

Answer 2

Answer:

D

Step-by-step explanation:

ap3x