How do you solve for r in ax + r = 7ax+r=7?

1 Answer
Tony B
Jun 1, 2016

See explanation

Explanation:

Given:" "ax+r=7 ax+r=7
color(green)("Using shortcut - based on consequence of first principles")Using shortcut - based on consequence of first principles

Move +ax+ax to the other side of the = but change the sign to minus

color(brown)(+ax+r=7) color(blue)(" "->" "r=7-ax)+ax+r=7 → r=7−ax

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
color(green)("Using first principles")Using first principles

Subtract color(blue)(ax)ax from underline("both sides.")

color(brown)(ax + r color(blue)(-ax)=7color(blue)(-ax))color(magenta)(" "larr" balanced equation")

But ax-ax=0

0+r=7-ax

r=7-ax

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