Download Quiz 3 - Fall 2005 - SOLUTIONS

Ivy Tech Community College
MAT 050 Internet
Quiz 3
SOLUTIONS
Solve the equation using the addition principle.
1) x + 4 = 11
-4
-4
x = 7
2) a - 15 = 0
+15
+15
a = 15
3) x + 9 = 5
-9
-9
x = -4
4) - 18.2 - s = 15.7
+s
+s
-18.2 = s + 15.7
-15.7
- 15.7
-33.9 = s
A) 33.9
B) - 33.9
C) -2.5
Decide if the given number is a solution to the given equation.
5) q + 8 = 12; 4
4 + 8 = 12 yes
A) Yes
B) No
Solve the equation using the addition principle.
6) x - 7 = 11
+7
+7
x = 18
Solve the equation using the multiplication principle.
7) -7a = 42
-7a/(-7) = 42/(-7)
a = -6
8) 12 = -3y
12/(-3) = -3y/(-3)
-4 = y
D) 2.5
9) 5y = -15
5y/5 = -15/5
x = -3
10) 1/12 a = 0
(12/1) 1/12 a = 0(12/1)
a=0
11)
- 1 /3 x = 7
3
(- /1)(- 1/3) x = 7(- 3/1)
x = -21
a
12) 0 = /-13
a
(-13) 0 = ( /-13)(-13)
0=a
Solve the equation.
13) 9y + 5 = -13
-5
-5
9y = -18
9y/9 = -18/9
y = -2
14) 4y + 9 = -3 + 8y
-8y
-8y
-4y + 9 = -3
-9
-9
-4y = -12
-4y/(-4) = -12/(-4)
y=3
1
A) /3
B) 3
44 = 10x - 6
+6
+6
50 = 10x
50/10 = 10x/10
5=x
A) 44
C) - 1/3
D) 2
C) 5
D) 10
C) 15
D) 3
15)
B) 40
16) 193 = 12x + 13
-13
-13
180 = 12x
180/12 = 12x/12
15 = x
A) 172
B) 168
Solve the equation. Clear fractions or decimals first.
17) 8x - ( 4x - 1) = 2
8x - 4x + 1 = 2
4x + 1 = 2
-1
-1
4x = 1
4x/4 = 1/4
x = 1/4
A) - 1/12
B) - 1/4
C) 1/12
D)
Solve the equation.
18) -7.8q + 1.2 = -29.8 - 1.6q
10(-7.8q + 1.2) = (-29.8 - 1.6q)10
-78q + 12 = -298 - 16q
+16q
+16q
-62q + 12 = -298
-12
-12
-62q
= -310
-62q/(-62) = -310/(-62)
q=5
A) 4.0
B) 5
C) -37
D) 4.2
19) - 8b + 9 + 6b = -3b + 14
- 2b + 9 = -3b + 14
+3b
+3b
b + 9 = 14
-9
-9
b = 5
A) 14
B) -14
C) 5
D) -9
1
/4
Solve the problem.
20) An adult and a child are on a seesaw 14 ft long. The adult weighs 175 lb. and the
child weighs 70 lb. How many feet from the child must the fulcrum be placed so that the
seesaw balances.
70L = (14 - L)175
70L = 2450 - 175L
+175L
+ 175L
245L = 2450
245L/245 = 2450/245
L = 10
A) 5
B) 10
C) 15
D) 20