Hayraidn
Answered

Magtanong at makakuha ng eksaktong mga sagot sa IDNStudy.com. Tuklasin ang malalim na sagot sa iyong mga tanong mula sa aming komunidad ng mga bihasang propesyonal.

the area of the concrete pathway is 350m2 and its perimeter pathway is 90 m.what is the length of the pathway????


Sagot :

[tex]Area: \ A=350 \ m^2 \\ \\ permeter: \ P = 90 \ m \\length: \ l \\ width : \ \ w \\ area : \ A=lw \\ perimeter : \ P=2l+2w \\\\\begin{cases}350=l\cdot w \\ 90=2l+2w \ \ / | \ divide \ each \ term \ by \ 2 \end{cases}[/tex]

[tex]\begin{cases}350=l\cdot w \\ 45= l+ w \end{cases}\\ \\\begin{cases}350=l\cdot w \\ l=45-w \end{cases}\\ \\ substitution \\\\350=(45-w) \cdot w\\ 350= 45w-w^2[/tex]

[tex]w^2-45w+350=0 \\\\w_{1}=\frac{-b-\sqrt{b^2-4ac}}{2a}=\frac{45-\sqrt{(-45)^2-4 \cdot 1\cdot 350}}{2 }=\frac{45-\sqrt{2025-1400}}{2 }=\\\\= \frac{45-\sqrt{625}}{2 }= \frac{45-25}{2 }=\frac{20}{2}=10\\\\w_{2}=\frac{-b+\sqrt{b^2-4ac}}{2a}=\frac{45+\sqrt{(-45)^2-4 \cdot 1\cdot 350}}{2 }= \frac{45-\sqrt{625}}{2 }= \frac{45+25}{2 }=\frac{70}{2}=35[/tex]
 
[tex]\begin{cases}w=10 \\l=45-w \end{cases} \ \ \ or \ \ \ \begin{cases}w=35 \\l=45-w \end{cases}\\\\\begin{cases}w=10 \\l=45-10 \end{cases} \ \ \ or \ \ \ \begin{cases}w=35 \\l=45-35 \end{cases}\\\\\begin{cases}w=10 \\l=35 \end{cases} \ \ \ or \ \ \ \begin{cases}w=35 \\l=10 \end{cases}\\\\Answer: \ \ \ Since \ this \ is \ a \ pathway, \ it \ makes \ sense \ that \ the \ width \ is \ the \ smaller \\ dimension, \ giving \ a \ width \ of \ 10 \ m \ and \ a \ length \ of \ 35\ m[/tex]