I'm going to use the substitution method.
If y = - 3/2 - 7, then:
1/2x + 5 = - 3/2x - 7
Combine like terms:
4/2x = - 12. Mutiply both sides by 2/4 to get x = -12 (2/4)
Simplify to get:
x = - 6.
Plug - 6 back in for x in either equation.
Y = 1/2( - 6) + 5 which becomes Y = - 3 + 5.
X = - 6, Y = 2
2 equations: the first one is the sum of 2 unknown numbers x and y: x + y = 72. Now the difference is 25, so x - y = 25. Solve the first equation for y: y = 72 - x. Sub that into the second equation to solve for x: x - (72 - x) = 25. x - 72 + x = 25 and 2x - 72 = 25. Therefore, 2x = 97 and x = 48.5 That's the larger of the 2 numbers; since we subtracted y from x we defined x as the larger of the 2. Just for fun, plug x in to find that y = 23.5
The correct two-way frequency table for the date will look like this:
RAP ROCK COUNTRY TOTAL
Grades 9-10 40 30 55 125
Grades 11-12 60 25 35 120
TOTAL 100 55 90 245
The sum of the row total is equal to the sum of the column total
125 + 120 = 100 + 55 + 90
245 = 245
5 + 8s = 15 + 3s
8s - 3s = 15 - 5
5s = 10
s = 10/5
s = 2 <=== they will charge the same at 2 sq ft
