Exercise 23 Page 9

To solve the equation, we have to isolate n on one side. Using the Division Property of Equality, we will divide both sides of the equation by - 0.8. This will eliminate the coefficient of n and isolate it on the right-hand side of the equation.

4=- 0.8n

DivEqn

.LHS /(- 0.8).=.RHS /(- 0.8).

4/- 0.8=- 0.8n/- 0.8

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Calculate quotient

MoveNegDenomToFrac

Put minus sign in front of fraction

- 4/0.8=- 0.8n/- 0.8

WriteAsFrac

Write as a fraction

- 4/810=- 0.8n/- 0.8

ReduceFrac

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

- 4/45=- 0.8n/- 0.8

DivByFracSL

.a /b/c.=a* c/b

- 4* 5/4=- 0.8n/- 0.8

ReduceFrac

a/b=.a /4./.b /4.

- 5/1=- 0.8n/- 0.8

DivByOne

a/1=a

- 5=- 0.8n/- 0.8

ReduceFrac

a/b=.a /(- 0.8)./.b /(- 0.8).

- 5=n/1

DivByOne

a/1=a

- 5=n

RearrangeEqn

Rearrange equation

n=- 5

To check that this solution is correct, let's substitute n= - 5 into the original equation and simplify.

4=- 0.8n

Substitute

n= - 5

4? =- 0.8( - 5)

MultNegNegOnePar

- a(- b)=a* b

4? =0.8(5)

Multiply

Multiply

4=4 ✓

Since the left-hand side and right-hand side are equal, n=- 5 is the correct solution.