Solve the simultaneous equations:
5x+3y=12
2x+y=5

I will use the substitution method, but you can also use elimination and matrix.

1. Solve for y in 2x+y=5
2x+y=5
y=5-2x

2. Substitute y=5-2x into 5x+3y=12
5x+3y=12
5x+3(5-2x)=12
5-x=12

3. Solve for x in 15-x=12
15-x=12
-x=12-15
-x=-3
x=3

4. Substitute x=3 into y=5-2x
y=5-2x
y=5-2*3
y=-1

5. Therefore, 
x=3
y=-1

Have a nice day :D

A) for the n row: 22+(n-1)×6therefore,b) 100-22=78that means (n-1)×6=7878÷6=1313+1=1414th row has 100 seats