When I had these kinds of problems, I'd count how many negatives there were. If there more or less negatives to positives, then it is negative. If there's the same amount of positives and negatives, then it's positive since they cancel out! The answer to this is A. (-2)(-4)(8)(-1)=-64.
Answer:
number of hours Alexander family ‘s sprinkler work = 20
number of hours Morgan family ‘s sprinkler work = 30
Step-by-step explanation:
Given in the question,
water output rate for the Alexander family ‘s sprinkler = 40 L
water output rate for the Morgan family ‘s sprinkler = 20 L
Suppose, number of hours Alexander family ‘s sprinkler work = x
Suppose, number of hours Morgan family ‘s sprinkler work = y
Equation1
x + y = 50
Equation 2
40x + 20y = 1400
x = 50 - y
Put this value of x in equation 2
40(50-y) + 20y = 1400
2000 - 40y + 20y = 1400
-20y = 1400 - 2000
-20y = -600
y = 30
Put this value of y in equation 1 to get the value of x
x + 30 = 50
x = 50 - 30
x = 20
Answer:
Step-by-step explanation:
6x-1=2x+5+4x-6
separate the variables in one side, numbers on the other side
6x-2x-4x=1+5-6
0=0
one solution
D.8
A and C are out because they would get you ether lower or equal to 20, which is equal to AC and your trying to find X in AB which is so posed to be the what equals AC+BC.
AB=AC+BC
5x=20+BC
5(8)=20+BC
40=20+BC
40=20+20
AC equals 20. AB will have to equal AC+ CB. If you put in A.4 in AB 5X you will get twenty and that not what you want. You want to get a number that will get you the an answer greater to AC. So 5(8)=40.
