Answer:
95
Step-by-step explanation:
step 1
Find out the total ball bearing ordered
Multiply the number of ball bearing boxes by the number of ball bearings in each box.

step 2
Find out the total springs ordered
Multiply the number of spring boxes by the number of springs in each box.

step 3
To find out how many more ball bearings than springs did they order, subtract the total number of springs from the total number of ball bearings

Im not for sure on this but i would say DF is 13
Answer:
Catherine's GPA is 2.48
Step-by-step explanation:
A z-score of 2.010 means that Catherine's GPA is 2.01 standard deviations above the mean. Therefore, Catherine's GPA is 
by the use of elimination method
make all coefficients of subject to be eliminated similar..by multiplying the coefficients with one another
for eqn(i)
5(-10y+9x=-9)
-50y+45x=-45
for eqn(ii)
9(10y+5x=-5)
90y+45x=-45
-50y+45x=-45
90y+45x=-45
...subtract each set from the other...
we get
-140y+0=0
y=0
from eqn(i)
10y+5x=-5
0+5x=-5
x= -1