Answer:
x = 6.5
Step-by-step explanation:
In order to solve this problem, you need to use trigonometry (sin, cosine, tangent).
Sin = opposite/hypotenuse
Cosine = adjacent/hypotenuse
Tangent = opposite/adjacent
We need to use tangent in this case because 10 is the opposite side from the 57° angle, and x is right next to it, making it adjacent. So, our equation would look like this:
tan (57)° = 10/x
Multiply both sides by x
x (tan (57)°) = 10
Divide both sides by tan (57)°
10 / tan (57)° = 6.49408 = 6.5
For this case, the first thing we must do is define variables.
We have then:
x: number of minutes
y: final temperature
We write then the equation that models the problem:
For y = 20 we have:
Clearing x:
Answer:
The temperature of the water will be 20 degree celcius after 150 minutes
(-8,-9)
Explanation:
y=2x+7 ; y=x-1
x-1=2x+7
x-1-7=2x+7-7
x-8=2x
x-x-8=2x-x
x=-8
y=x-1
y=-8-1
y=-9
Keeping in mind that the element labeling is row,column, thus 2,1 simply means the 2nd row and 1st column, thus