81.
Solve the equation 4(3
�
−2)=404(3
x
−2)=40
.
Answer
: �
=4
x
=4
.
82.
Calculate the value of �
y
in the equation 5
�
4+6=18
45
y
+6=18
.
Answer
: �
=12
y
=12
.
83.
Find the volume of a cone with radius 55
units and height 88
units (use �
=3.14
π
=3.14
).
Answer
: Volume = 13×
�
×
�
2× =13×3.14×52×8=209.33
ℎ
31
×
π
×
r
2
×
h
=
31
×3.14×5
2
×8=209.33
cubic units.
84.
Determine the value of �
z
if 8
�
+7=718
z
+7=71
.
Answer
: �
=8
z
=8
.
85.
Solve the equation 3
�
2−4=10
23
x
−4=10
.
Answer
: �
=14
x
=14
.
86.
Evaluate the expression: 112−7×411
2
−7×4
.
Answer
: 112−7×4=121−28=9311
2
−7×4=121−28=93
.
87.
Calculate the area of a circle with a radius of 1212
units (use �
=3.14
π
=3.14
).
Answer
: Area = �
×
�
2=3.14×122=452.16
π
×
r
2
=3.14×12
2
=452.16
square units.
88.
Solve the inequality: 5
�
−3>225
x
−3>22
.
Answer
: �
>5
x
>5
.
89.
Find the slope of the line parallel to �
=25
�
−3
y
=
52
x
−3
.
Answer
: The slope of a line parallel to this line remains 25
52
.
90.
Solve for �
y
in the equation 27
�
+5=9
72
y
+5=9
.
Answer
: �
=14
y
=14
.
