Joe is 20 years old. his sister is half his age less 7. how old is his sister?

i think the answer is 3 but i'm not sure

1234567891011 match the reasons with the statements in the proof. given: j | | k m 1 = m 3 prove: l | | m 1. j||k, m∠3 = m∠1 if lines are ||, then corresponding angles are =. 2. m∠1 = m∠2 if alternate interior angles are =, then lines are ||. 3. m∠2 = m∠3 substitution 4. l||m given

Graph the equation by plotting point x=2

Solve x+3y=6 and 4x-6y=6 by elimination . show work !