Question

If y is directly proportional to x and y=5 when x=2, find the value of y when x =7​

Answer 1

y = 17.5

Explanation:

y = kx

→ Substitute in the values

5 = 2k

→ Divide both sides by 2 to isolate k

k = 2.5

⇒ y = 2.5x

→ Substitute in x = 7

y = 2.5x ⇔ y = 2.5 × 7 ⇔ y = 17.5