Answer:
The value of y is 18 at x = 70
Step-by-step explanation:
The equation of the directly proportional is y = k x, where k is the constant of proportionality.
∵ The value of y is directly proportional to the value of x
→ By using the equation above
∴ y = k x
∵ x = 140 and y = 36
→ Substitute them in the equation above
∴ 36 = k(140)
∴ 36 = 140k
→ Divide both sides by 140
∵ [tex]\frac{36}{140}[/tex] = k
∴ [tex]\frac{9}{35}[/tex] = k
→ Substitute the value ok in the equation
∴ y = [tex]\frac{9}{35}[/tex] x ⇒ equation of proportionality
∵ x = 70
→ Substitute in the equation to find y
∴ y = [tex]\frac{9}{35}[/tex] × 70
∴ y = 18
∴ The value of y is 18 at x = 70
