Wrote and solve an equation to find the number.The difference of twice a number and 7 is 9

Mathematics

1 answer:

andrew11 [14]2 years ago

6 0

n - 7 = 9

Step-by-step explanation:

so basically just make up a random variable and place it for the "twice a number" then u sovle it as a 2 step equation

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Write the equation that describes the line in slope-intercept form: slope= 4, point (3,-2) is on the line

docker41 [41]

Slope intercept form is y=mx+b
m=slope
b=y intercept

slope is 4
y=4x+b
subsitute if iin (x,y) form
so x=3 and y=-2 is one solution
subsitute
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3 years ago

Integrate 1 - x / x(x2 + 1) d x by partial fractions.

solniwko [45]

Answer:

$log x-\frac{log(x^{2}+1) }{2}-tan^{-1} x$

Step-by-step explanation:

step 1:- by using partial fractions

$[tex]\frac{1-x}{x(x^{2}+1) } =\frac{A(x^{2}+1)+(Bx+C)(x }{x(x^{2}+1) }$ ......(1)

step 2:-

solving on both sides

$1-x=A(x^{2} +1)+(Bx+C)x......(2)$

substitute x =0 value in equation (2)

1=A(1)+0

A=1

comparing x^2 co-efficient on both sides (in equation 2)

0 = A+B

0 = 1+B

B=-1

comparing x co-efficient on both sides (in equation 2)

-1 = C

step 3:-

substitute A,B,C values in equation (1)

now

$\\\int\limits^ {} \, \frac{1-x}{x(x^{2}+1) } d x =\int\limits^ {} \frac{1}{x} d x +\int\limits^ {} \frac{-x}{x^{2}+1 } d x -\int\limits \frac{1}{x^{2}+1 } d x$