Multiplication Equations
Equations Multiplication Lgafn to solvewholenumbermultiPlication cquations.
Nine-bandedarmadillosare alwaysborn in grouPsof 4. If you count32 babies,what is the number of mother armadillos? To put togetherequal grouPsof 4, multiply. Let t??representthe number of mother armadillos. Therewill be m equal groupsof 4. You can use the equation4m = 32. Division is the inverseof multiplication. To solvean equation that containsmultiplication,use division to "undo" the multiplication.
/////t 4 m m e a n s" 4 X m . "
4m=32 4m 4
32 -1
There are B mother armadillos.
n1 = $
EX A M P L E #
SolvingMultiplicationEquations Solveeach equation. Checkyour answers'
A-, 3 x = 1 2 3x=12 3x - 12 3 3 x=4 T2
Check 3x t
T2
3(4) I
t2/
t2
3tB=4w B=4tu
9_!t! 4
4
2 = w 4w
Check B 2
B
4(2)
9
B
Br' 2-7 Multiplication Equations
81
GUTDED PRACTICE Example
Solve each equation. Check your answers. 2 . 2 7= 3 w 1. 7x = 2I 4.56=7b
Example
3 . 9O = LUa 5. 1 2 = 2 n
5.3c=33
7. The areaof a rectangulardeck is 675 squarefeet.The deck'swidth is 15 feet.\Mhatis its length?
INDEPENDENT PRACTTCE Example
Example
Solveeach equation. Check your answers. 9. 52 = I3a 8. IZp - 36
10. 64 = Bn
11. 20 = 5x
12. 6r = 30
13. 77-- rrt
14. 14s= 98
15. I2m = I32
16. 9z = I35
17. Marcy spreadsout a rectangularpicnic blanket with an areaof 24 squarefeet. Its width is 4 feet.lVhat is its length?
PRACTTCE AND PROBLEM SOLVING Solve each equation. 19. IB = 2y 18. 5y = 35
20. 54 = 9!
21. ISy - 12s
22.4y=0
23. 22y - 440
24. 3y = 63
2 5 .z - 6 = 3 4
26. 6y = Il4
27. 16I - 7!
28. 135 = 3/
29. y - 15= 3
30. Bl = 9/
3 1 .4 + y = 1 2
32. 7y -- 2I
3 3 .a + 1 2 = 2 6
34. 10x = 120
35. 36 = l2x
3 6 .s - 2 - - 7
3 7 . 1 5+ t = 2 1
38. Estimation Coloradois almost a perfect rectangleon a map. Its border from eastto west is about 387 mi, and its areais about 104,247mi2. Estimatethe length of Colorado'sborder from north to south. (Area = length x width)
WYOMING
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2-7 Multiplication Equations
83
Nine-bandedarmadillosare alwaysborn in grouPsof 4. If you count32 babies,what is the number of mother armadillos? To put togetherequal grouPsof 4, multiply. Let t??representthe number of mother armadillos. Therewill be m equal groupsof 4. You can use the equation4m = 32. Division is the inverseof multiplication. To solvean equation that containsmultiplication,use division to "undo" the multiplication.
/////t 4 m m e a n s" 4 X m . "
4m=32 4m 4
32 -1
There are B mother armadillos.
n1 = $
EX A M P L E #
SolvingMultiplicationEquations Solveeach equation. Checkyour answers'
A-, 3 x = 1 2 3x=12 3x - 12 3 3 x=4 T2
Check 3x t
T2
3(4) I
t2/
t2
3tB=4w B=4tu
9_!t! 4
4
2 = w 4w
Check B 2
B
4(2)
9
B
Br' 2-7 Multiplication Equations
81
GUTDED PRACTICE Example
Solve each equation. Check your answers. 2 . 2 7= 3 w 1. 7x = 2I 4.56=7b
Example
3 . 9O = LUa 5. 1 2 = 2 n
5.3c=33
7. The areaof a rectangulardeck is 675 squarefeet.The deck'swidth is 15 feet.\Mhatis its length?
INDEPENDENT PRACTTCE Example
Example
Solveeach equation. Check your answers. 9. 52 = I3a 8. IZp - 36
10. 64 = Bn
11. 20 = 5x
12. 6r = 30
13. 77-- rrt
14. 14s= 98
15. I2m = I32
16. 9z = I35
17. Marcy spreadsout a rectangularpicnic blanket with an areaof 24 squarefeet. Its width is 4 feet.lVhat is its length?
PRACTTCE AND PROBLEM SOLVING Solve each equation. 19. IB = 2y 18. 5y = 35
20. 54 = 9!
21. ISy - 12s
22.4y=0
23. 22y - 440
24. 3y = 63
2 5 .z - 6 = 3 4
26. 6y = Il4
27. 16I - 7!
28. 135 = 3/
29. y - 15= 3
30. Bl = 9/
3 1 .4 + y = 1 2
32. 7y -- 2I
3 3 .a + 1 2 = 2 6
34. 10x = 120
35. 36 = l2x
3 6 .s - 2 - - 7
3 7 . 1 5+ t = 2 1
38. Estimation Coloradois almost a perfect rectangleon a map. Its border from eastto west is about 387 mi, and its areais about 104,247mi2. Estimatethe length of Colorado'sborder from north to south. (Area = length x width)
WYOMING
1 I
I
?
l
II I I
l-3g7
m;-l
2-7 Multiplication Equations
83
