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 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}`