- #1
navneet9431
My question is about basic algebra. I am thinking about the "why" here and I'm looking for an intuitive answer.If you have the following equations:
=>S+U=90
=>S+U=90
and
=>40S+25U=2625
=>40S+25U=2625
you can then rewrite S=90−U and then substitute.
Now you have a single equation with one variable:
=>40(90−U)+25=2625
=>3600−40U+25U=2625
=>−15U=−975
Hence, U=65What's going on here? Ultimately, why does this always solve out? I realize single equations with one variable solve (there's got to be some number that satisfies this equation), but why? What's going on? I guess by solving the equation, we're bypassing this repetitive process of trial and error of plugging in numbers and seeing if it equals 2625? Is that what "solving the equation" really means?
Note: I am a High School student and English is my second language.Thanks!
=>S+U=90
=>S+U=90
and
=>40S+25U=2625
=>40S+25U=2625
you can then rewrite S=90−U and then substitute.
Now you have a single equation with one variable:
=>40(90−U)+25=2625
=>3600−40U+25U=2625
=>−15U=−975
Hence, U=65What's going on here? Ultimately, why does this always solve out? I realize single equations with one variable solve (there's got to be some number that satisfies this equation), but why? What's going on? I guess by solving the equation, we're bypassing this repetitive process of trial and error of plugging in numbers and seeing if it equals 2625? Is that what "solving the equation" really means?
Note: I am a High School student and English is my second language.Thanks!