Answer:
Step-by-step explanation:
xy=-30
y=-30/x
x+y=-4
x-30/x=-4
x²-30=-4x
x²+4x-30=0


The signs of the numbers in the problem matter because if a number is negative in the equation than you're answer could be negative. ex. -3/9= -3 but if the negative sign wasn't there than the answer would be wrong bc the answer would be positive.
hope thats what you need hope it helps.
Answer:
2
Step-by-step explanation:
We have
n = 4 scores
SS = 48
For this question, we are required to find the estimated standard error
To get this, we first solve for the variance
S² = SS/n-1
= 48/4-1
= 48/3
= 16
Then S² = 16
S = √16
S = 4
Then the estimated standard error is given by:
S/√n
= 4/√4
= 4/2
= 2.
The estimated standard error is 2.
So paid160
75 percent off
100 percent=original
75 percent off=100-75=25%
160=25% of original cost
'of' means multiply
remember tha tpercent is parts out of 100 so
25%=25/100=1/4
160=1/4 times original cost
multily both sides by 4
640=original cost
answe ris $640 =original cost