Answer:
55
Step-by-step explanation:
let x be her dad's age then Anna is [tex]\frac{1}{5}[/tex] x + 7
In 19 years
dad's age is x + 19 and Anna's age = [tex]\frac{1}{5}[/tex] x + 7 + 19 = [tex]\frac{1}{5}[/tex] x + 26
Then her dad is twice as old as her
2 ([tex]\frac{1}{5}[/tex] x + 26) = x + 19 , distribute parenthesis
[tex]\frac{2}{5}[/tex] x + 52 = x + 19 ( multiply through by 5 to clear the fraction )
2x + 260 = 5x + 95 ( subtract 2x from both sides )
260 = 3x + 95 ( subtract 95 from both sides )
165 = 3x ( divide both sides by 3 )
55 = x
That is her dad is 55 years old and Anna is 18
