Question

If y varies directly with x when y=8,x=20 find the value of x when y=42

Answer 1

The value of x is 105 when y=42

Step-by-step explanation:

A direct proportion means that the change in one quantity will also cause the change in other quantity

Given

y varies directly with x

x ∝ y

when the proportionality symbol is removed a proportionality constant is introduced

$x=ky\\k=\frac{x}{y}\\Putting\ y=8\ and\ x=20\\k=\frac{20}{8}\\k = \frac{5}{2}\\So,\ the\ equation\ will\ be\\x=\frac{5}{2}y\\Putting\ y=42\\x=\frac{5}{2}*42\\x=5*21\\x= 105$

The value of x is 105 when y=42

Keywords: Proportion, Direct variation

Learn more about proportion at:

• brainly.com/question/3398261
• brainly.com/question/3614284

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