Question

Please help me with this..

Answer 1

Answer:

f = 1

Step-by-step explanation:

Use the method of cross- multiplication

$\frac{a}{b}$ = $\frac{c}{d}$ ⇒ ad = bc, thus

20f = 5(f + 3) ← distribute

20f = 5f + 15 ( subtract 5f from both sides )

15f = 15 ( divide both sides by 15 )

f = 1