<span>1)
11x+5y=20
2x+5y=-25
multiply the second equation by - 1 and add the result with the first equation:
11x + 5y = 20
- 2x - 5y = 25
-------------------
9x = 45
=> x = 45 / 9
=> x = 5
Replace in </span><span>2x+5y=-25
=> 2(5) + 5y = - 25
5y = - 25 - 10
5y = - 35
y = - 35 / 5
y = - 7
2)
3x+7y=-21
3x-7y=63</span>
Add the two equations:
3x + 3x + 0 = - 21 + 63
6x = 42
=> x = 42 / 6
=> x = 7
Replace in <span>3x-7y=63
3(7) - 7y = 63
=> 7y = 21 - 63
=-> 7y = - 42
=> y = - 42 / 6
=> y = - 7</span>
Answer:
144g
Step-by-step explanation:
Make a ratio:
15:108
20:x
cross multiply
15x = 2160
x = 144
Answer:
Step-by-step explanation:
Answer:
See explanation
Step-by-step explanation:
Prove equality
Consider left and right parts separately.
<u>Left part:</u>
<u>Right part:</u>
Hence
Since left and right parts are the same, the equality is true.
F(x) = -9 + 10.3x probably.
It's definitely not the first or last option as they have negative gradients (i.e. negative x-coefficient) and so represent a negative correlation. The data given tells us there is a positive gradient and so a positive correlation.
It could be the second option as the second and third are not so vastly different but I would go for the third because it appears to most closely fit the data pattern.