Which represents a reduction?

A
(x,y) —> (0.9x, 0.9y)

B
(x,y) —> (1.4x, 1.4y)

C
(x,y) —> (0.7x, 0.3y)

D
(x,y) —> (2.5x, 2.5y)

11
Which set of lengths are not the side
lengths of a right triangle?

A
28, 45, 53

B
13, 84, 85

C
36, 77, 85

D
16, 61, 65

i dont know them pls help me

3 answers

well, the scale factors must be the same for an expansion or reduction.
And of course, for a reduction, the scale must be less than 1, right?

For the Pythagorean triples a,b,c, you must have
a^2 + b^2 = c^2
where c is the largest of the three values.
So, check the triples to see which doesn't fit the bill.
For example, 13^2 + 84^2 = 169 + 7056 = 7225 = 85^2
thanks and i think the first one is a?
yes, it is