4. Serenity is four years younger than twice her brother's age. Serenity is 18 years old. Which model and solution best represents x, the age of Serenity's brother?
X7
-
JOOL
7
=
DOS
X=11
JE
COS
11

The party planning committee has to determine the number of tables needed for an upcoming event. if a square table can fit 8 people and a round table can fit 6 people, the equation 150 = 8x + 6y represents the number of each type of table needed for 150 people.

I’m really confused and need to learn this

42. if 20 men can eat 200 kg of wheat in 40 days, then 10 men can eat 300 kg of wheat in how many days? a) 120 days b) 60 days c) 80 days d) none of these