<span>4x – 20 = 900
4x = 900+20
4x = 920
x = 920/4
x = 230
he earned $230
</span>
Answer:
See explanation
Step-by-step explanation:
Consider given statement "If a figure is a cube, then it has eight vertices" in math terms. Let
- statement p be "A figure is cube.";
- statement q be "A figure has 8 vertices."
Then the statement "If a figure is a cube, then it has eight vertices" can be written as

Converse (
): If a figure has eight vertices, then it is a cube.
Inverse (
): If a figure is not a cube, then it has not eight vertices.
Contrapositive (
): If a figure has not eight vertices, then it is not a cube.
Step-by-step explanation:
(x²-1)(x+1)≥0
As it has two multiples,
Therefore,
Either,
x²-1≥0
x²≥0+1
x²≥1
x≤√1
x≤1
Or,
x+1≥0
x≥-1