To solve the equations in terms of fractions, we need to know the inverse operations.
Note :
To clear the fraction for multiplication, we will multiply it by the reciprocal of the given term.
Problem 1 :
(1/2)t + (1/4) = 5/16
Solution :
Subtract 1/4 from both sides
(1/2)t + (1/4) – (1/4) = (5/16) – (1/4)
(1/2)t = 1/16
Multiply both sides by 2
(1/2t) (2) = (1/16) (2)
t = 1/8
Problem 2 :
(5/6s) + (2/9) = -7/12
Solution :
Subtract 2/9 from both sides
(5/6)s + (2/9) – (2/9) = (-7/12) – (2/9)
LCM of 12, 9 is 108
(5/6)s = (-87/108)
Multiply both sides by 6/5
(5/6)s (6/5) = (-87/108) (6/5)
s = -29/30
Problem 3 :
3/4 = (5/6)a + 2/9
Solution :
By Swap,
(5/6)a + 2/9 = 3/4
Subtract 2/9 from both sides
(5/6)a + (2/9) – (2/9) = (3/4) – (2/9)
LCM of 4, 9 is 36
(5/6)a = 19/36
Multiply both sides by 6/5
(5/6)a (6/5) = (19/36) (6/5)
a = 19/30
Problem 4 :
5/8 = (1/10) + (5/14)m
Solution :
By Swap,
(1/10) + (5/14)m = 5/8
Subtract 1/10 from both sides
(1/10) - (1/10) + (5/14)m = (5/8) – (1/10)
LCM of 8, 10 is 80
(5/14)m = 21/40
Multiply both sides by 14/5
(5/14)m (14/5) = (21/40) (14/5)
m = 147/100
Problem 5 :
(-41/60) + (17/20)p = 29/30
Solution :
Add 41/60 to both sides
(-41/60) + (41/60) + (17/20)p = (29/30) (41/60)
LCM of 30, 60 is 60
(17/20)p = 99/60
Multiply both sides by 20/17
(17/20)p (20/17) = (99/60) (20/17)
p = 33/17
Problem 6 :
3/8 = (-1/4)x – (3/5)
Solution :
(-1/4)x – (3/5) = 3/8
Add 3/5 to both sides
(-1/4)x – (3/5) + (3/5) = (3/8) + (3/5)
LCM of 8, 5 is 40
(-1/4)x = 39/40
Multiply both sides by -4
(-1/4)x (-4) = (39/40) (-4)
x = -39/10
Problem 7 :
(-3/2)t – (5/6) = -4/9
Solution :
Add 5/6 to both sides
(-3/2)t – (5/6) + (5/6) = (-4/9) + (5/6)
LCM of 9, 6 is 54
(-3/2)t = 7/18
Multiply both sides by -2/3
(-3/2)t (-2/3) = (7/18)(-2/3)
t = -7/27
Problem 8 :
(-3/5)z – 4 = -77/20
Solution :
Add 4 to both sides
(-3/5)z – 4 + 4 = (-77/20) + 4
(-3/5)z = 3/20
Multiply both sides by -5/3
(-3/5)z (-5/3) = (3/20) (-5/3)
z = -1/4
Problem 9 :
4w + (2/7) = -4/5
Solution :
Subtract 2/7 from both sides
4w + (2/7) – (2/7) = (-4/5) – (2/7)
LCM of 5, 7 is 35
4w = -38/35
Multiply both sides by 1/4
(4w) (1/4) = (-38/35) (1/4)
w = -19/70
Problem 10 :
On a test, you correctly answer six 5-point questions and eight 2-point questions. You earn 92% of the possible points on the test. How many points p is the test worth?
Solution :
Number of 5 point questions = 6, so 6 x 5 ==> 30
Number of 2 point questions = 8, so 2 x 8 ==> 16
Total = 30 + 16
= 46
Let p be number of points. By attending the questions you have recieved 92% of marks.
46 : p = 92 : 100
46/p = 92/100
Doing cross multiplication, we get
92p = 46(100)
p = 46(100)/92
p = 50
So, worth of the test is a total of 50 points.
Problem 11 :
A slush drink machine fills 1440 cups in 24 hours.
a. Write and solve an equation to find the number c of cups each symbol represents.
b. To lower costs, you replace the cups with paper cones that hold 20% less.
Write and solve an equation to find the number n of paper cones that the machine can fill in 24 hours.
Solution :
a) Number of cups filled in 24 hours = 1440
Each symbol represents c cups. Number of symbols = 30
Total number of cups = 1440/30
= 48
So, each symbol will represent 48 cups.
b) Each paper cone will hold 80% of original quantity.
In 24 hours the machine can fill 1440 cups.
Number of cups filled in 1 hour = 1440/24
= 60 cups per hour
To find the number of paper cones, first calculate the volume of one paper cone:
Volume of one paper cone
= 60 cups * 0.8 = 48 cups/hour.
Now, divide the total number of cups by the volume of one paper cone to find the number of cones filled in 24 hours:
n = 1440 cups / 48 cups/hour
= 30 cones
Problem 11 :
Forty-five basketball players participate in a tournament. Write and solve an equation to find the number of 3-person teams that they can form.
Solution :
Number of basket player = 45
Let x be the number of teams which has 3 persons in each team.
3x = 45
x = 45/3
x = 15
So, there will be 15 teams.
May 21, 24 08:51 PM
May 21, 24 08:51 AM
May 20, 24 10:45 PM