Answer:
The required inequality is
.
Jhon can buy at most 5 books.
Step-by-step explanation:
Consider the provided information.
Part(A)
Let b represent the number of books John buys.
He wants at least $10 in his savings account which means if we subtract the cost of books from $40 we have at least $10 left.

The required inequality is
.
Part(B)




Part(C): Jhon can buy at most 5 books.
Answer:
t=1
Step-by-step explanation:
combine the one t and the 4t
16-2t=5t+9
subtract the 16
-2t=5t+9-16
-7t=9-16
-7t=-7
t=1
The answer is C: systematic sampling
A) Vertical angles are congruent: It is true. Vertical angles are called opposite angles, so they are congruent.
B) Angles with measures between 0- 90 degrees are complementary: It is false. Complementary angles are angles that the sum of their value is 90°
C) Straight angles are complementary: it is false. Straight angles are angles which value is 180°.
D) Angles with measure between 90 and 180 degrees are obtuse. This statement is true by definition
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