There is one solution:
use elimination method
5x - 7y = 12
5y - 2x = -7 ---> change equation around
5x - 7y = 12
-2x + 5y = -7
2 x ( 5x - 7y) = 2 x (12) multiply both sides by 2
5 x (-2x +5y) = 5 x (-7)
this give you
10x - 14y =24
-10x+25y = -35 add down
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11y = - 11 x is eliminated to find y value
y = -1 input to one of the original equations
5(-1) - 2x = -7
-5 - 2x = -7
+5 +5 add 5 to both sides
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-2x = -2
x = 1
your coordinates for when they intersect is at (1, -1)
one solution
Answer:
a). 59.049°C
b). 2.1179 seconds
Step-by-step explanation:
Expression representing the final temperature after decrease in temperature of the metal from 100°C to T°C is,
T = 
where x = duration of cooling
a). Temperature when x = 5 seconds
T = 100(0.9)⁵
= 59.049
≈ 59.049°C
b). If the temperature of the metal decreases from 100°C to 80°C
Which means for T = 80°C we have to calculate the duration of cooling 'x' seconds
80 =
0.8 = 
By taking log on both the sides
log(0.8) =log[]
-0.09691 = x[log(0.9)]
-0.09691 = -0.045757x
x = 
x = 2.1179
x ≈ 2.1179 seconds
Let's use the equation 5x - 20 = 10 as an example for this.
To work backwards from this, you would add the same amount to each side.
You want to isolate the 5x so that you can solve for x.
To do that, you would add 20.
But again, you must add and subtract the same amount to both sides.
So it would look a bit like this:
5x - 20 + 20 = 10 + 20
That would simplify to 5x = 30, or in other words, x = 6.
Basically, you isolate the multiple of the variable then divide the answer to the equation from that multiple.
In the example, 5 is the multiple and after isolating it, the answer was 30.
30 ÷ 5 = 6
x = 6
Hope this helps :)
Step 1: Put the numbers in order.
1,2,5,6,7,9,12,15,18,19,27<span>Step 2: </span>Find the median (How to find a median).
1,2,5,6,7,9,12,15,18,19,27<span>Step 3: </span>Place parentheses around the numbers above and below the median.
Not necessary statistically–but it makes Q1 and Q3 easier to spot.
(1,2,5,6,7),9,(12,15,18,19,27)<span>Step 4: </span>Find Q1 and Q3
Q1 can be thought of as a median in the lower half of the data. Q3 can be thought of as a median for the upper half of data.
(1,2,5,6,7), 9, ( 12,15,18,19,27). Q1=5 and Q3=18.<span>Step 5: </span>Subtract Q1 from Q3 to find the interquartile range.
18-5=13.
Hope this helped:)
-BRIEMODEE:)
