Exercise 19 Page 46

An equation that has two or more variables is called a literal equation. To rewrite a literal equation, we need to solve for one variable in terms of the other variable(s). In this exercise we are asked to solve for y.

2x-4y=20

SubEqn

LHS-2x=RHS-2x

2x-4y-2x=20-2x

SubTerms

Subtract terms

- 4y=20-2x

DivEqn

.LHS /(- 4).=.RHS /(- 4).

- 4y/- 4=20-2x/- 4

MovePartNumRight

a* b/c=a/c* b

- 4/- 4y=20-2x/- 4

QuotOne

a/a=1

y=20-2x/- 4

▼

Simplify RHS

WriteDiffFrac

Write as a difference of fractions

y=20/- 4-2x/- 4

MovePartNumRight

a* b/c=a/c* b

y=20/- 4-2/- 4x

CalcQuot

Calculate quotient

y=- 5-2/- 4x

MoveNegNumToFrac

Put minus sign in front of fraction

y=- 5-( - 2/4) x

NegNeg

- (- a)=a

y=- 5+2/4x

ReduceFrac

a/b=.a /2./.b /2.

y=- 5+1/2x

We have isolated y on the left-hand side of the equation and simplified the expression on the right-hand side.