Answer:
i like how to tell us to answer something with no file
Step-by-step explanation:
Answer:
Step-by-step explanation:
integral(x/(1+x^2)^2)dx
=(1/2)integral(2x/(1+x^2)^2)dx
=(1/2)[-1/(1+x^2)] +c
Answer:
15 25 25 65
10 05 20 35
25 30 45 100
First column is 6th grade, second is 7th, third is 8th and the last column is total
-2<em>x</em> + 6<em>y</em> = -38
3<em>x</em> - 4<em>y</em> = 32
To solve by elimination, multiply the top equation by 3 and the bottom equation by 2.
3(-2<em>x</em> + 6<em>y</em> = -38) --> -6<em>x</em> + 18<em>y</em> = -114
2(3<em>x</em> - 4<em>y</em> = 32) --> 6<em>x</em> - 8<em>y</em> = 64
Add the equations.
-6<em>x </em>+ 18<em>y</em> = -114
6<em>x</em> - 8<em>y</em> = 64
+_____________
0 + 10<em>y</em> = -50
10<em>y</em> = -50
<em>y</em> = -5
Substitute -5 for y into one of the original equations to find x.
3<em>x</em> - 4<em>y</em> = 32
3<em>x</em> - 4(-5) = 32
3<em>x</em> + 20 = 32
3<em>x</em> = 12
<em>x</em> = 4
Check work by plugging the <em>x</em>- and <em>y</em>-values into both of the original equations.
-2<em>x</em> + 6<em>y</em> = -38
-2(4) + 6(-5) = -38
-8 - 30 = 38
38 = 38
3<em>x</em> - 4<em>y</em> = 32
3(4) - 4(-5) = 32
12 + 20 = 32
32 = 32
Answer:
<em>x</em> = 4 and <em>y</em> = -5; (4, -5).
