The correct option is B. Distributive property
Given,
On solving the above equation,
multiplying both sides by 3 we, get

now subtracting 21 from both the sides,

dividing both the sides by 2 we get,

Since in the above steps we follow all the giving property except the distributive property.
Hence the correct option is B. Distributive property.
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Answer: 
Step-by-step explanation:



Answer:
Option D is correct that is The Slopes of two lines are negative reciprocals.
Step-by-step explanation:
Perpendicular lines are the lines which intersect each other at right angle or make 90° angle with each other.
we that the Slope of perpendicular lines are equal to -1
Therefore, Option D is correct that is The Slopes of two lines are negative reciprocals.
Answer:
Choice A x= 16, y= 9√2
Step-by-step explanation:
x= 9+7 =16
y= √9²*2= 9√2
Short leg = x-6m
Longer leg =x
Hypotenuse = x+6m
x² + (x-6)² =(x+6)²
x² + x²-12x+36 = x²+12x+36
2x²-12x+36= x² +12x+36
2x²-12x+36-36= x² +12x+36-36
2x² - 12x-12x = x²+12x-12x
2x² -24x-x² = x²-x²
x² -24x = 0
x(x-24)=0
x = 24
Short leg = 24-6m = 18
Longer leg =24
Hypotenuse = 24+6m=30
Check
a² + b² = c²
18² +24² =30²
324 +576 = 900
900=900