Answer:
The sorted steps are;
1) Write the equations: 10·x + 8·y = 472 and 9·x + 8·y = 456
2) Multiply to get one variable to eliminate: -90·x - 72·y = -4248 and 90·x + 80·y = 4560
3) Eliminate x's: 8·y = 312
4) Solve for y: y = 39 (39 buses)
5)Plug back in to find x: 10·x + 8·(39) = 472
6) Solve for x: x = 16 (16 vans)
Step-by-step explanation:
Let x = The number of students in each van and y = The number of students in each bus
We have;
For High School A;
10·x + 8·y = 472...(1)
For High School B;
9·x + 8·y = 456...(2)
Multiply equation (1) by (-9) and equation (2) by 10 to get
(10·x + 8·y) × (-9) = 472 × (-9)
-90·x -72·y = -4,248...(3)
9·x + 8·y × (10)= 456 × (10)
90·x + 80·y = 4,560...(4)
Add equation (3) to (4) gives;
-90·x -72·y + 90·x + 80·y = -4,248 + 4,560
90·x - 90·x -72·y + 80·y = -4,248 + 4,560
8·y = 312
y = 312/8 = 39
y = 39
Substituting the value of y in equation (1), gives;
10·x + 8·y = 10·x + 8 × 39 = 472
10·x + 312 = 472
10·x = 472 - 312 = 160
10·x = 160
x = 160/10 = 16
x = 16
The number of students in each van = x = 16 students
The number of students in each bus = y = 39 students.