Exercise 33 Page 85

How can you isolate r on the left-hand side?

r=-1/2

Practice makes perfect

To solve the equation we need to isolate r on one side of the equation. By dividing both sides by 5, we can cancel 7 from the left-hand side.

7r=-7/2

DivEqn

.LHS /7.=.RHS /7.

r=.-7/2 /7.

DivFracSL

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

r=-7/14

ReduceFrac

a/b=.a /7./.b /7.

r=-1/2

Therefore, r=- 12 is the solution to the equation. To check that we have the correct solution, we can substitute r=- 12 into the original equation and simplify.

7r=-7/2

Substitute

r= -1/2

7 ( -1/2) ? =-7/2

MoveNegDenomToNum

Put minus sign in numerator

7(-1/2)? =-7/2

MoveLeftFacToNum

a*b/c= a* b/c

7(-1)/2? =-7/2

Multiply

- 7/2? =-7/2

MoveNegNumToFrac

Put minus sign in front of fraction

-7/2=-7/2

Since the left-hand side and right-hand side are equal, r=- 12 is the correct solution.

Subchapter links

Lesson Check p.85

Practice and Problem-Solving Exercises p.85-87

Standardized Test Prep p.87

Mixed Review p.87

Exercise 33 Page 85

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