Answer:
{x,y,z} = {-18,4,2}
Step-by-step explanation:
Solve equation [2] for the variable x
x = -10y + 2z + 18
Plug this in for variable x in equation [1]
(-10y+2z+18) + 9y + z = 20
- y + 3z = 2
Plug this in for variable x in equation [3]
3•(-10y+2z+18) + 27y + 2z = 58
- 3y + 8z = 4
Solve equation [1] for the variable y
y = 3z - 2
Plug this in for variable y in equation [3]
- 3•(3z-2) + 8z = 4
- z = -2
Solve equation [3] for the variable z
z = 2
By now we know this much :
x = -10y+2z+18
y = 3z-2
z = 2
Use the z value to solve for y
y = 3(2)-2 = 4
Use the y and z values to solve for x
x = -10(4)+2(2)+18 = -18
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Answer:
25 girls
Step-by-step explanation:
Let
x denote number of boys
and
y denote number of girls
According to the statement that total 45 people came,
x+y = 45 => Eqn 1
And total paid amount was 175
So,
5x + 3y = 175 => Eqn 2
For solving, We will use the substitution method
So, from eqn 1
x = 45-y
Putting value of x in eqn 2
5(45-y) +3y = 175
225 - 5y + 3y = 175
-2y+225 = 175
-2y = 175-225
-2y = -50
2y = 50
y = 25
Putting y =25 in eqn 1
x+25 = 45
x = 45 - 25
x = 20
As y= 25
So, 25 girls came to the dance ..
Answer: c= $( 5 x 5.20)
Step-by-step explanation:
Given: Total people =5
Money paid by each person = $5.20
Total cost of the sundae = (Number of people ) x (Money paid by each person)
Total cost of sunday : c= 5 x ($5.20)
i.e.Total cost of sunday = $(5 x 5.20)
i.e.Total cost of sunday = $ 26
Hence, the required equation to represent the total cost (c) of the sundae:
c= $( 5 x 5.20)