# SOLUTION: Please help me to solve the following equations: Solve each formula for the indicated variable: 18) I= E/R+r for R Please find the value of the indicated variable:

Algebra ->  Algebra  -> Polynomials-and-rational-expressions -> SOLUTION: Please help me to solve the following equations: Solve each formula for the indicated variable: 18) I= E/R+r for R Please find the value of the indicated variable:       Log On

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 Question 88386: Please help me to solve the following equations: Solve each formula for the indicated variable: 18) I= E/R+r for R Please find the value of the indicated variable: Please show a complete solution to each problem. 36) Ride the peaks. Smith bicycled 45 miles going east from Durango, and Jones bicycled 70 miles. Jones averaged 5 miles per hour than smith, and his trip took one-half hour longer that Smith's. How fast was each one traveling? Thank you so much for your assistanceAnswer by ankor@dixie-net.com(15638)   (Show Source): You can put this solution on YOUR website!solve each formula for the indicated variable: : Assume you mean: I = for R : Multiply both sides by (R+r) and you have: I(R+r) = E : Divide both sides by I and you have: R + r = : Subtract r from both sides: R = - r : : 36) Ride the peaks. Smith bicycled 45 miles going east from Durango, and Jones bicycled 70 miles. Jones averaged 5 miles per hour than smith, and his trip took one-half hour longer that Smith's. How fast was each one traveling? : Kind of a poorly worded problem, I interpret it to mean: It took Jones a half hour longer to travel 70 mi than Smith to travel 45 mi : Let s = smith's speed then (s+5) = Jone's speed : Write a time equation;Time = Dist/time : Smith's 45 mi time + half hr = Jone's 70 mi time + = : Multiply equation by 2s(s+5) to get rid of the denominators, we have: 45*2(s+5) + s(s+5) = 70*2s : 90s + 450 + s^2 + 5s = 140s : s^2 + 90s + 5s - 140s + 450 = 0 : s^2 - 45s + 450 = 0; a quadratic equation : Factors to: (s - 15)(s - 30) = 0 : s = 15 and s = 30 : Check both solutions s = 15, then j = 20 45/15 = 3 hr 70/20 = 3.5 hr and s = 30, j = 35 45/30 = 1.5 hrs 70/35 = 2.0 hr : Interesting that both solution work, isn't it?