1.
Storing milk at temperatures smaller than 35°F can affect its quality of taste.
hence t > 35°F
storing milk at temperatures greater than 40°F is an unsafe food practice. hence
t < 40°F
so correct choice is
C. t > 35 AND t < 40
2.
15| x-7|+4=10|x-7|+4
subtracting 4 both side
15| x-7|+4- 4 =10|x-7|+4 - 4
15| x-7| = 10|x-7|
this is possible when |x-7| = 0
hence x - 7 = 0
x = 7
hence correct choice is
C. only x=7
3.
|x+1|+5=2
we know that , |x+1| ≥ 0
adding 5 both side
|x+1| + 5 ≥ 0 + 5
|x+1| + 5 ≥ 5
hence the relation |x+1|+5=2 is false.
C. no solution
|4x+12|=0
4x+12 = 0
x = -12/4
x = - 3
hence B. solution
|3x|=9
3x =
9
x =
9/3
x =
3
hence
A. two solutions