Aschool has 18 classes with 35 students in each class. in order to reduce class size to 30, how many new classes must be formed?

18*35 - number of the students at school.

x- is a number of classes if it is going to be 30 students per class, then

30x - number of the students at school.

So,

18*35 = 30x

x=(18*35)/30 = 21 classes should be if it is going to be 30 students per class.

21 - 18 = 3 new classes must be formed.

19.side- angle- side

20. angle- side- angle

step-by-step explanation:

arrange the equations with like terms in columns.

analyze the coefficients of x or y.

add the equations and solve for the remaining variable.

substitute the value into either equation and solve.

check the solution.

step-by-step explanation: