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CaHeK987 [17]
3 years ago
11

Solve by the substitution method 7x+6y = -17 -3x+y =18

Mathematics
1 answer:
Novay_Z [31]3 years ago
3 0
6 is your answer so it's like this x=3 y=6 or x=6 y=3
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Leila's soccer team has 8 players on it. there are 40 players in the league. how many teams are playing in the league?
bazaltina [42]
There are 5 teams playing in the league
8 0
3 years ago
Read 2 more answers
Marianne has been collecting donations for her biscuit stall at the school summer fayre. There are some luxury gift tins of bisc
LenaWriter [7]
<span>Answer:

Number of luxury gift tins of biscuits sold at £5 each: 18
Number of normal packets sold at £1 each: 2
Number of mini- packs of 2 biscuits sold at 10p each: 80

Solution:

Number of luxury gift tins of biscuits sold at £5 each: x
Amount received by the number of luxury gift tins of biscuits sold: £5 x Number of normal packets sold at £1 each: y
Amount received by the number of normal packets sold: £1 y
Number of mini- packs of 2 biscuits sold at 10p each: z
Amount received by the number of 2 biscuists sold: 10p z =£0.1z

She tells Amy that she has received exactly 100 donations in total:
(1) x+y+z=100

A collective value of £100:
Total amount receibed: £5 x + £1 y+ £0.1z= £100 → £ (5x+1y+0.1z)= £100 → 5x+y+0.1z=100 (2)

Her stock of £1 packets is very low compared with the other items:
y<<x
y<<z
Then we can despice the value of "y" and solve for "x" and "z":
y=0:
(1) x+y+z=100→x+0+z=100→x+z=100 (3)
(2) 5x+y+0.1z=100→5x+0+0.1z=100→5x+0.1z=100 (4)

Solving the system of equations (3) and (4) using the substitution method:
Isolating z in equation (3): Subtrating x from both sides of the equation:
(3) x+z-z=100-x→z=100-x

Replacing z by 100-x in the equation (4):
(4) 5x+0.1z=100→5x+0.1(100-x)=100
Eliminating the parentheses:
5x+0.1(100)-0.1x=100→5x+10-0.1x=100
Adding similar terms on the left side of the equation:
4.9x+10=100
Solving for x: Subtrating 10 from both sides of the equation:
4.9x+10-10=100-10→4.9x=90
Dividing both sides of the equation by 4.9:
4.9x/4.9=90/4.9→x=18.36734693

Replacing x=18.36734693 in the equation:
z=100-x→z=100-18.36734693→z=81.63265306

We can round x and z: x=18 and z=81 and solve for y in equations (1) and (2):
(1) x+y+z=100→18+y+81=100
Adding similar terms on the left side of the equation:
99+y=100
Subtracting 99 from both sides of the equation:
99+y-99=100-99→y=1

(2) 5x+y+0.1z=100→5(18)+y+0.1(81)=100→90+y+8.1=100→98.1+y=100→98.1+y-98.1=100-98.1→y=1.9→y=2 different to 1

Suppose y=1. Replacing y=2 in equations (1) and (2):
(1) x+y+z=100→x+1+z=100→x+1+z-1=100-1→x+z=99
(2) 5x+y+0.1z=100→5x+1+0.1z=100→5x+1+0.1z-1=100-1→5x+0.1z=99

Repeating the process:
z=99-x
5x+0.1z=99→5x+0.1(99-x)=99→5x+9.9-0.1x=99→4.9x+9.9=99→4.9x+9.9-9.9=99-9.9→4.9x=89.1→4.9x/4.9=89.1/4.9→x=18.18367346
z=99-18.18367346→z=80.81632653
x=18 and z=80
(1) x+y+z=100→18+y+80=100→y+98=100→y+98-98=100-98→y=2
(2) 5x+y+0.1z=100→5(18)+y+0.1(80)=100→90+y+8=100→y+98=100→y+98-98=100-98→y=2

Answer:
Number of luxury gift tins of biscuits sold at £5 each: 18
Number of normal packets sold at £1 each: 2
Number of mini- packs of 2 biscuits sold at 10p each: 80 </span>
5 0
3 years ago
Read 2 more answers
Simplify 3x -5 + 25x-9
mash [69]

Answer:

28x - 14

Step-by-step explanation:

3x - 5 + 25x - 9

= 28x - 14

3 0
3 years ago
Read 2 more answers
pen costs twice as much as a pencil. The total cost of 1 1 pen and 1 1 pencil is $2.10 $ 2 . 10 . If p represents the cost of 1
dybincka [34]

Answer : The equation could you use to find p is, 2p+p=2.10

Step-by-step explanation :

Let the cost of 1 pen be, 'x'

and the cost of 1 pencil is, 'p'

As we are given that total cost of 1 pen and 1 pencil is $2.10. The equation will be:

x+p=2.10    ............(1)

And we have also given that the pen costs twice as much as a pencil. The equation will be:

x=2p    ............(2)

Now put the equation 2 in equation 1, we get:

x+p=2.10

2p+p=2.10

Thus, the equation could you use to find p is, 2p+p=2.10

3 0
3 years ago
Read 2 more answers
Give one example of when you would. use the friendly numbers strategy to subtract .Explain why ?
lord [1]
Say you were solving 27 + 19. If you were planning on using the friendly numbers strategy, you'd look at the first <span>addend, 27, and determine that</span> the closest "friendly number" here is thirty, which you'd get by adding 3. From there, you can jump to the next friendly number, forty, by adding another 10. So far you'd've added 13, and you'd need another 6 for that too add up to 19, your second addend. After adding 3, 10, and 6 to 27, you'd find your sum, or "final answer"- 46.

I hope this was what you were looking for!
5 0
3 years ago
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