I need help on my math problem

X+ y = 5 ; x - y =3 solve using linear combination

How are algebraic expressions evaluated using substitution?

City l has a temperature of −3 °f. city m has a temperature of −7 °f. use the number line shown to answer the questions: number line from negative 8 to positive 8 in increments of 1 is shown. part a: write an inequality to compare the temperatures of the two cities. (3 points) part b: explain what the inequality means in relation to the positions of these numbers on the number line. (4 points) part c: use the number line to explain which city is warmer. (3 points)