Question

indique qual deve ser o valor do numero x para que se tenha a) 7/9 = x/45
b)45/63 = 5/x

Answer 1

$a) \\ \frac{7}{9} = \frac{x}{45} \\ \\ 9x=7.(45) \\ \\ 9x=315 \\ \\ x=315\div9 \\ \\ \fbox{ x=35 }$ 

$b) \\ \frac{45}{63} = \frac{5}{x} \\ \\ 45x=5.(63) \\ \\ 45x=315 \\ \\ x=315\div45 \\ \\\fbox{ x=7 }$