Transcript Solve Equations with Multiplication and Division

Objective
The student will be able to:
solve equations using multiplication and
division.
Designed by Skip Tyler, Varina High School
Goal of solving
equations:
To get the variable by itself!!!
To do this you should always remove
the number or numbers on the side with
the variable by using inverse or opposite
operations!
Designed by Skip Tyler, Varina High School
1) Solve. -5t = 60
To get the variable by itself, which
number needs to be moved?
-5
To move the -5, you have to do the opposite
operation. What operation will we use? The
variable “t” is being multiplied so the
opposite operation is ___________.
division
1.
2.
3.
4.
1) Solve -5t = 60
-5 -5
Draw “the river” to
t = -12
separate the equation
into 2 sides
Divide both sides by -5
Simplify
Check your answer
-5(-12) = 60
1.
2.
3.
4.
2) Solve 15 = 6n
6
6
Draw “the river”
Divide both sides by 6
2.5 = n
Simplify
Check your answer
15 = 6(2.5)
3) Solve -3v = -129
1.
2.
3.
4.
v = -126
v = -43
v = 43
v = 126
Answer Now
x
 12
4) Solve
4
To get the variable by itself, which number needs to be
moved?
4
To move the 4, you have to do the opposite operation.
What operation will we use? The variable “x” is
being divided so the opposite operation is
___________.
multiplication
.
1.
2.
3.
4.
x
4) Solve  12
4
Draw “the river”
x
Multiply both sides by 4
4 ·  12 · 4
Simplify
4
Check your answer
x = -48
48
 12
4
1.
2.
3.
4.
5.
6.
2x
5) Solve
= 18
3
2x
3·
= 18 · 3
Draw “the river”
3
Multiply both sides by 3
Simplify
Divide both sides by 2
Simplify
Check your answer
2x = 54
2
2
x = 27
2(27)
 18
3
6) Which step clears the fraction in
3b
 12
5
1.
2.
3.
4.
Multiply by 3
Multiply by 5
Multiply by -12
Multiply by -5
Answer Now
7) Solve
1.
2.
3.
4.
b = -56
b = -14
b = 14
b = 56
Answer Now
4b
 8
7