4. 7
5. 9.6

1. -6
2. -27
3. -8
4. 3
5. 16
6. -64
7. 2.4

1. -10x
2. 9a+14b
3. 2R+3R^2
4. 60a^3
5. 5x^3+5x^4y

6. 2y

1. m=15
2. y=-13
3. x=11
4. E=12
5. X=4
6. x=-5.2
7. x=7

system solution: x=-2 and y=5

WORD PROBLEMS
1. A = (1/2)bh
A = (1/2)(2x+1)(x+5) or (1/2)(2x^2 + 7x + 5)

2. c=10

3. The machine will produce 720 pieces in 9 hours.
The tank will contain 2400 gal of water.

4. y = x-4 and 3xy=231
SO 3x(x-4)=231
3x^2-12x = 231
3x^2-12x-231=0
so in ax^2 + bx + c = 0
a=3
b=-12
c=-231

substitute and solve: the two dimensions are 11 and 7