 Math homework I need help - Printable Version +- School Survival Forums (http://forums.school-survival.net) +-- Forum: Learning, Youth Rights and School Survival (/forumdisplay.php?fid=3) +--- Forum: Homework Help & Answers (/forumdisplay.php?fid=30) +--- Thread: Math homework I need help (/showthread.php?tid=28394) Math homework I need help - Luizao876 - 02-01-2013 07:10 AM I suck in proportions, so if anybody here can help, I will be grateful. Here are the questions ( the ?/? are fractions): B) m/15 = n/6, m - n = 90 C) r/s = 13/5 , r - s = 72 D) 18/x = 8/y, x + y = 104 E) x/8 = y/3 = z/4, x - y + z = 108 F) 15/x = 9/y = 3/z, x - y - z = 42 This is middle school stuff I think, so it shouldn't be so hard to solve them if you are good in Math. I will be grateful for whoever does this for me. Math homework I need help - Desu - 02-01-2013 07:46 AM I'm too lazy to do these right now, but, the general way you do these is: 1) rearrange the proportions such that you get the variables in the numerator. 2) on the right side, (m-n = 90 etc.) solve for one variable 3) use that information and put it into the proportion like for B) m-n = 90 m = 90 + n Therefore, substitute m = 90 + n for m (90 + n) / 15 = n / 6 dive 90 + n by 15 6 + (n / 15) = n / 6 subtract n / 15 from both sides 6 = (n / 6) - (n / 15) Solve for n. Once you have n, put n back into the original equation you start with, then solve for m. RE: Math homework I need help - Luizao876 - 02-01-2013 08:17 AM Thanks for the help Desu, I was able to finish all of the homework. RE: Math homework I need help - Heil_Kaiba8921 - 02-02-2013 05:20 AM freaking smart-ass middle schools...this is what we were learning last semester and i sucked at them because the teacher was dull, demanded respect and never gave you any, and literally put me to sleep even if i was wide awake. I ended up getting a 57% in his class so i'm in the repeat class for algebra 2 with a better teacher (i know because i had him before and used to go to him all the time for help during study hall)...i do wish that i would have worked just slightly harder to be able to have passed first semester RE: Math homework I need help - SmokeyTheAggie - 02-02-2013 07:22 AM I solved F for ya. x = 210, y = 126, z = 42