Answer:
Step-by-step explanation:
x-y=7
-3x+9y=-39
Divide the second equation by 3
-x +3y = -13
Add this to the first equation
x-y=7
-x +3y = -13
----------------------
0x +2y = -6
Divide by 2
2y/2 = -6/2
y = -3
Now find x
x-y = 7
x -(-3) = 7
x+3 = 7
Subtract 3 from each side
x = 4
(4,-3)
Or by substitution
x-y=7
solve for x
x = 7+y
-3x+9y=-39
Substitute y+7 in for x
-3(7+y) +9y = -39
Distribute
-21 -3y +9y = -39
Combine like terms
-21 +6y = -39
Add 21 to each side
6y = -18
Answer:
The area of this figure is 45 square units.
Answer:
102 students
Step-by-step explanation:
Note that 65% and 71% are both 1 standard deviation from the mean (71%). According to the empirical rule, 68% of scores lie within 1 std. dev. of the mean.
68% of 150 students would be 0.68(150 students) = 102 students
Recall that the area under a curve and above the x axis can be computed by the definite integral. If we have two curves
<span> y = f(x) and y = g(x)</span>
such that
<span> f(x) > g(x)
</span>
then the area between them bounded by the horizontal lines x = a and x = b is
To remember this formula we write
Answer: 49
Step-by-step explanation:
50−16/4+3
=50−4+3
=46+3
=49
