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Exercises Word problems and geometry

Example 9.62 from Prealgebra, 9.7 Solve a Formula for a Specific Variable

Solve a Formula for a Specific Variable: example 9.62

Solve the formula $3 x + 2 y = 18$ for $y :$

ⓐ when $x = 4$
ⓑ in general

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Solution

when x = 4 in general

Write the equation.

Substitute any given values.

Simplify if possible.

Subtract to isolate the y-term.

Simplify.

Divide.

Simplify.

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Solve the formula $3 x + 4 y = 10$ for $y :$

ⓐ when $x = 2$
ⓑ in general

How did it go?

PreviousSolve a Formula for a Specific Variable: example 9.61 Next Solve a Formula for a Specific Variable: example 9.63

From Prealgebra (1st edition) by OpenStax (Rice University), section 9.7, licensed under CC BY 4.0. Original at openstax.org. We split the solution into steps; the words, numbers and figures are the book's. OpenStax doesn't endorse this site.