Answer:
<em>Grades to be scored in 3rd exam = 88</em>
Step-by-step explanation:
Given that average of 3 numbers is 85.
First two numbers are 81 and 86.
To find:
3rd number so that average is 85
Solution:
Let the third number = 
Formula for average is:

Here, sum of numbers = 
Total count of numbers = 3

<em>Grades to be scored in 3rd exam = 88</em>
Answer:
Step-by-step explanation:
Jack's method is equivalent because of the "law of commutative property", which means that multiplication problems have the same result no matter the order.
2x5 is the same as 5x2
Answer:
-7
Step-by-step explanation:
The solution to the given system of equation is (25/7, 6/7)
<h3>System of equation</h3>
Given the system of equation expressed as:
x= - 4y+7 ........... 1
-2y+3x=9 ...........2
Substitute the equation 1 into 2 into have:
-2y + 3(-4y+7) = 9
-2y + 3(-4y) + 3(7) = 9
-2y - 12y + 21 = 9
Collect the like terms
-14y = 9- 21
-14y = -12
y = 6/7
Substitute y = 6/7 into equation 1;
x =-4y + 7
x = -4(6/7) + 7
x= -24/7 + 7
x = -24+49/7
x = 25/7
Hence the solution to the given system of equation is (25/7, 6/7)
Learn more on system of equation here; brainly.com/question/14323743
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240 miles
d=48(5) which equals 240