Isolate the x. Subtract 3x from both sides, and add 4 to both sides
-2x (-3x) - 4 (+4) < 3x (-3x) + 21 (+4)
-2x - 3x < 21 + 4
Simplify. Combine like terms
-5x < 25
Isolate the x. Divide -5 from both sides (remember to flip the sign).
-5x/-5 < 25/-5
x > 25/-5
x > -5
x > -5 is your answer
hope this helps
Let's start b writing down coordinates of all points:
A(0,0,0)
B(0,5,0)
C(3,5,0)
D(3,0,0)
E(3,0,4)
F(0,0,4)
G(0,5,4)
H(3,5,4)
a.) When we reflect over xz plane x and z coordinates stay same, y coordinate changes to same numerical value but opposite sign. Moving front-back is moving over x-axis, moving left-right is moving over y-axis, moving up-down is moving over z-axis.
A(0,0,0)
Reflecting
A(0,0,0)
B(0,5,0)
Reflecting
B(0,-5,0)
C(3,5,0)
Reflecting
C(3,-5,0)
D(3,0,0)
Reflecting
D(3,0,0)
b.)
A(0,0,0)
Moving
A(-2,-3,1)
B(0,-5,0)
Moving
B(-2,-8,1)
C(3,-5,0)
Moving
C(1,-8,1)
D(3,0,0)
Moving
D(1,-3,1)