Answer:
-30/7 = x
Step-by-step explanation:
im guessing u mean (3x+5)/(2x+7) = 5
3x+5 = 5(2x+7)
3x+5=10x+35
-7x=30
x= -30/7
recall your d = rt, distance = rate * time.
let's say we have two trains, A and B, A is going at 85 mph and B at 65 mph.
they are 210 miles apart and moving toward each other, at some point they will meet, when that happens, the faster train A has covered say d miles, and the slower B has covered then the slack from 210 and d, namely 210 - d.
When both trains meet, A has covered more miles than B because A is faster, however the time both have been moving, is the same, say t hours.
![\bf \begin{array}{lcccl} &\stackrel{miles}{distance}&\stackrel{mph}{rate}&\stackrel{hours}{time}\\ \cline{2-4}&\\ \textit{Train A}&d&85&t\\ \textit{Train B}&210-d&65&t \end{array}\\\\ \dotfill\\\\ \begin{cases} \boxed{d}=85t\\ 210-d=65t\\[-0.5em] \hrulefill\\ 210-\boxed{85t}=65t \end{cases} \\\\\\ 210=150t\implies \cfrac{210}{150}=t\implies \cfrac{7}{5}=t\implies \stackrel{\textit{one hour and 24 minutes}}{1\frac{2}{5}=t}](https://tex.z-dn.net/?f=%20%5Cbf%20%5Cbegin%7Barray%7D%7Blcccl%7D%20%26%5Cstackrel%7Bmiles%7D%7Bdistance%7D%26%5Cstackrel%7Bmph%7D%7Brate%7D%26%5Cstackrel%7Bhours%7D%7Btime%7D%5C%5C%20%5Ccline%7B2-4%7D%26%5C%5C%20%5Ctextit%7BTrain%20A%7D%26d%2685%26t%5C%5C%20%5Ctextit%7BTrain%20B%7D%26210-d%2665%26t%20%5Cend%7Barray%7D%5C%5C%5C%5C%20%5Cdotfill%5C%5C%5C%5C%20%5Cbegin%7Bcases%7D%20%5Cboxed%7Bd%7D%3D85t%5C%5C%20210-d%3D65t%5C%5C%5B-0.5em%5D%20%5Chrulefill%5C%5C%20210-%5Cboxed%7B85t%7D%3D65t%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5C%5C%20210%3D150t%5Cimplies%20%5Ccfrac%7B210%7D%7B150%7D%3Dt%5Cimplies%20%5Ccfrac%7B7%7D%7B5%7D%3Dt%5Cimplies%20%5Cstackrel%7B%5Ctextit%7Bone%20hour%20and%2024%20minutes%7D%7D%7B1%5Cfrac%7B2%7D%7B5%7D%3Dt%7D%20)
Answer:
P(x) = x³ - 3x² - 5x + 15
Step-by-step explanation:
∵ The roots of the polynomial are -√5 , √5 , 3
∴ The polynomial has 3 factors:
(x - √5) , (x + √5) , (x - 3)
∴ P(x) = (x - √5)(x + √5)(x - 3)
= (x² + √5x - √5x - 5)(x - 3)
= (x² - 5)(x - 3) = x³ - 3x² - 5x + 15
∴ P(x) = x³ - 3x² - 5x + 15
Answer:
AA similarity theorem
Step-by-step explanation:
we know that
<u>AA (Angle-Angle) Similarity</u> states that In two triangles, if two pairs of corresponding angles are congruent, then the triangles are similar
In this problem we have that
∠BCA=∠ECD ----> by vertical angles
∠BAC=∠DEC ---> because AB is parallel to ED (alternate interior angles)
therefore
Triangles ABC and EDC are similar by AA similarity theorem
Add like terms and then simplify
