Answer:

Step-by-step explanation:






Find the soluiton
2x+2y=16
3x-y=4
x+y=8
<u>3x-y=4+</u>
4x=12
x=3
3(3)-y=4
9-y=4
y=5
(3,5)
test them to see if get true statment
obviously the first equatons of 1,2,4 work
1 doesn't work
2, works
4. doesn't work
2 is the same as the first except both euations are just doubled
answer is 2
Answer:
number of $20 bill = 4
Number of $5 bill = 5
Step-by-step explanation:
Given that:
Total number of $5 and $20 bills = 9
Let :
Number of $5 bills = x
Number of $20 bills = y
Combined worth of all bills = $105
x + y = 9 - - - (1)
5x + 20y = 105 - - - (2)
From (1)
x = 9 - y
Substitute x = 9 - y into (2)
5(9 - y) + 20y = 105
45 - 5y + 20y = 105
15y = 105 - 45
15y = 60
y = 60/15
y = 4
x = 9 - y
x = 9 - 4 = 5
Hence,
number of $20 bill = 4
Number of $5 bill = 5
Answer:
8 9.8 - 6.4n
9 15 - j/2
Step-by-step explanation:
8
2.8 - 4.4n - 2n +7
= 2.8+7 -4.4n -2n
= 9.8 - 6.4n
9
11 + (-3) - 1/8 j - 3/8 j +7
= 11 - 3 - 1/8 j - 3/8 j + 7
= 11 - 3 + 7 - 1/8 j - 3/8 j
= 15 - 4/8 j
= 15 - j/2