Rafael writes an expression to represent “a number, n, decreased by thirty-one.” Then he evaluates that expression if n = 29. Which statements are true about the expression and its evaluation? Check all that apply. The correct expression is 31 minus n.
This is a subtraction expression.
This is an addition expression.
To evaluate, substitute 29 for the variable in the expression.
To evaluate, substitute 31 for the variable in the equation.
To evaluate the expression, add 31 to 29.
The correct expression is n minus 31.
To evaluate the expression, subtract 31 from 29.

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.