Answer:
1 x=-2.5 y = -5.5
2. x=5 y=1
Step-by-step explanation:
1) What is the solution of the given system?
5x-y=-7
3x-y=-2
Multiply the second equation by -1
-1*(3x-y)=-1(-2)
-3x +y = 2
Now add the first equation to the modified second equation
5x-y=-7
-3x +y = 2
------------------
2x = -5
Divide each side by 2
2x/2 = -5/2
x = -2.5
Now we need to find y
-3x+y =2
-3(-2.5) +y =2
7.5 +y =2
Subtract 7.5 from each side
7.5 -7.5 +y =2-7.5
y = -5.5
2) what is the solution of the given system?
5x+7y=32
8x+6y=46
Divide the second equation by 2
8x/2+6y/2=46/2
4x+3y =23
Multiply the first equation by 4
4 (5x+7y)=32*4
20x+28y = 128
Now multiply the modified 2nd equation by -5
-5(4x+3y )=-5(23
)
-20x -15y = -115
Lets add the new equations together to eliminate x
20x+28y = 128
-20x -15y = -115
---------------------
13y = 13
Divide each side by 13
13y/13 =13/13
y=1
Now substitute back in to find x
5x+7y=32
5x +7(1) =32
5x +7 =32
Subtract 7 from each side
5x+7-7 =32-7
5x =25
Divide by 5
5x/5 =25/5
x=5
Idk but the web always helps me so you can ask that question online
Answer:
A=10 cm
B=5 cm
Area of square = 25 cm
Step-by-step explanation:
Since that is an equilateral triangle based off the fact that all the sides are the same variable (a) then that means 30 divided by 3 which equals 10. So now we know that a = 10. Lets input that information for the rectangle. Since there are 2 a's that equals 20 and the perimeter is 30 so b has to be 5 since 5 times 2 is 10 plus 20 equals 30. so now we know that a=10 and b=5 so our squares sides are all 5. The area of the square is 25
Answer:
Given that The data to represent average test scores for a class of 16 students includes an outlier value of 78.
We can find sum of all 16 test scores = 84(16) = 1344
Outlier found = 78
If outlier is removed new sum = 1344-78 = 1266
Number of entries without outlier = 15
New average = 1266/12 =84.4
We find that average of new data increases.
Also whenever we remove outlier std deviation also would be reduced.
Step-by-step explanation:
Answer:
119
Step-by-step explanation:
The nearest whole numbers from those listed are
10
3
106
The estimated sum = 119
The actual sum is 118.668
When you are doing a test, being able to estimate is a very powerful skill. 119 is close enough to the actual answer that you know your actual answer is likely correct.
