2/5 - 4/5 + -9/10 =

, will mark brainliest for answer with an explanation

Step-by-step explanation:

-2/5 - 4/5 + -9/10

= -2/5 - 4/5 - 9/10

= {-2(2) -4(2) - 9)/10

= (-4 - 8 - 9)/10

= -21/10

= -2 1/10

Step-by-step explanation:

(A)

When cross multiply the fractions, we get

⇒ 4 × 4 = 9 × 9

⇒ 16 ≠ 36

So,  do not form a proportion.

(B)

When cross multiply the fractions, we get

⇒ 4 × 13 = 6 × 11

⇒ 52 ≠ 66

So,  do not form a proportion.

(C)

When cross multiply the fractions, we get

⇒ 4 × 25 = 10 × 10

⇒ 100 = 100

So,  form a proportion.

(D)

When cross multiply the fractions, we get

⇒ 3 × 25 = 9 × 5

⇒ 75 ≠ 45

So,  do not form a proportion.