Please help

first question:

Which mathematical property is demonstrated?

5⋅7⋅4=5⋅4⋅7

associative property of addition

commutative property of addition

commutative property of multiplication

associative property of multiplication

2nd question:

Which expressions are equivalent to 4⋅(7⋅y)?

(choose all correct answers)

1. (7⋅y)⋅4

2. 4⋅7+4⋅y

3. (4⋅7)⋅y

4. 28y

5. 4⋅7⋅4⋅y

Last question
is 3(a−b) and 3a−3b Equivalent? yes/no

is 2a(2+b) and 4ab Equivalent? Yes/no

THANK YOU!!!

Statement reason 1. δabc is similar to δced. given 2. 3. definition of slope 4. slope of slope of definition of slope 5. slope of × slope of multiplying the slopes 6. slope of × slope of substitution property of equality 7. slope of × slope of simplifying the right side the table contains the proof of the relationship between the slopes of two perpendicular lines. what is the reason for statement 2? a. parallel line segments that meet a common perpendicular line are proportional in length. b. the lengths of vertical and horizontal sides in congruent triangles are in a common ratio. c. trigonometric identities determine the lengths of the legs in a right triangle. d. corresponding side lengths in similar triangles are proportional in length.