Exercise 36 Page 20

Practice makes perfect

a To solve the equation, we have to perform inverse operations on both sides of the equation until the variable is isolated.

8x+1=- x-1

AddEqn

LHS+x=RHS+x

9x+1=-1

SubEqn

LHS-1=RHS-1

9x=-2

DivEqn

.LHS /9.=.RHS /9.

x=-2/9

MoveNegNumToFrac

Put minus sign in front of fraction

x=-2/9

b Again, let's try to isolate x.

-4x-3=3x-4-7x

SimpTerms

Simplify terms

-4x-3=-4x-4

AddEqn

LHS+4x=RHS+4x

-3≠ -4

We got a contradiction, so this equation has no solution.

c Again, let's isolate x.

4-5x=1+6x

SubEqn

LHS-6x=RHS-6x

4-11x=1

SubEqn

LHS-4=RHS-4

-11x=-3

MultEqn

LHS * (- 1)=RHS* (- 1)

11x=3

DivEqn

.LHS /11.=.RHS /11.

x=3/11

d Like in Parts A-C, we will isolate x.

7-x+3=9x+10

AddTerms

Add terms

10-x=9x+10

SubEqn

LHS-9x=RHS-9x

10-10x=10

SubEqn

LHS-10=RHS-10

-10x=0

MultEqn

LHS * (- 1)=RHS* (- 1)

10x=0

DivEqn

.LHS /10.=.RHS /10.

x=0

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