Answer: Option B
She should use the fact that the
opposite sides of a parallelogram are
congruent and then use the
Pythagorean theorem.
We cannot use the diagonals of square property because this is a rectangle, opposite angles will also not work, and we cannot use the diagonal property because thats what we have to prove.
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Answer: 
Step-by-step explanation:
Answer:
= 5 ( 12d + 23f )
Step-by-step explanation:
-2(5d-9f)+7f-10(-9f-7d
Open parenthesis
= -10d + 18f + 7f + 90f + 70d
Collect like terms
= -10d + 70d + 18f + 7f + 90f
= 60d + 115f
Factorise
= 5 ( 12d + 23f )
Therefore,
-2(5d-9f)+7f-10(-9f-7d) in its simplest form is 5 ( 12d + 23f )