Your teacher asked your class to describe a real world situation in which a y-intercept is 50 and the slope is -10. Your partner gave the following description: My friend started with $50 and earned $10 every week from doing chores. What mistake did your partner make?

Hi, again!
First blank: multiplication property of equality
Both sides of the equation were multiplied by (1/2). 

Second blank: m<E
Angle E is an inscribed angle intercepting arc FGD, so by the inscribed angle theorem, its measure is half the measure of the arc.

Third blank: m<G
Same explanation as the prior blank

Fourth blank: substitution property of equality
Since angle E is equal to half the measure of arc FGD, we can replace that term. Likewise with angle G.