9/21 because it can still be reduced to 3/7
Answer:
Step-by-step explanation
Hello!
3x/4 + 6=42
3x/4=42-6 = 36
3x = 36*4
3x = 144
x= 144/3 =48
3/4 of 48 = (48*3) / 4 =36
36+6=42
the original number is 48
Answer:
x = -1,5
Step-by-step explanation:
2x² - 8x - 10
2x² - 10x + 2x - 10
2x(x - 5) + 2(x - 5)
(x - 5)(2x + 2)
x = 5 x = -2/2
x = -1,5
Answer: 
Step-by-step explanation:
Given
Radius of cylinder 
The height of the cylinder is 
The surface area of a cylinder is 
If only the outer is considered then, the area required is

Rewrite the boundary lines <em>y</em> = -1 - <em>x</em> and <em>y</em> = <em>x</em> - 1 as functions of <em>y </em>:
<em>y</em> = -1 - <em>x</em> ==> <em>x</em> = -1 - <em>y</em>
<em>y</em> = <em>x</em> - 1 ==> <em>x</em> = 1 + <em>y</em>
So if we let <em>x</em> range between these two lines, we need to let <em>y</em> vary between the point where these lines intersect, and the line <em>y</em> = 1.
This means the area is given by the integral,

The integral with respect to <em>x</em> is trivial:

For the remaining integral, integrate term-by-term to get

Alternatively, the triangle can be said to have a base of length 4 (the distance from (-2, 1) to (2, 1)) and a height of length 2 (the distance from the line <em>y</em> = 1 and (0, -1)), so its area is 1/2*4*2 = 4.