The television set has a rectangular shape. The diagonal of this rectangle along with its width and length together form a right angular triangle.
This means that we can apply the Pythagorean theorem which states that:
(diagonal)^2 = (length)^2 + (width)^2
Let the width be w. We know that the length is 0.75 times the width, this means that: length = 0.75 w
Substitute in the above equation:
(20)^2 = (0.75w)^2 + (w)^2
400 = 0.5625 w^2 + w^2
400 = 1.5625 w^2
w^2 = 256
w = 16
This means that the width of the screen is 16 in.
Step-by-step explanation:
area of rectangle=length×breadth=(2x+3)(3x+7)
=6x²+9x+14x+21=6x²+23x+21
Using polynomial long division, we get
3x^3+6x^2+11x
_____________
(x+2) | 3x^4-x^2+cx-2
-(3x^4+6x^3)
____________
6x^3-x^2+cx-2
- (6x^3+12x^2)
_____________
11x^2+cx-2
-(11x^2+22x)
__________
(22+c)x-2.
If you're wondering how I did the long division, what I essentially did was get the first value (at the start, it was 3x^4) and divided it by the first value of the divisor (which in x+2 was x) to get 3x^3 in our example. I then subtracted the polynomial by the whole divisor multiplied by, for example, 3x^3 and repeated the process.
For this to be a perfect factor, (x+2)*something must be equal to (22+c)x-2. Focusing on how to cancel out the 2, we have to add 2 to it. To add 2 to it, we have to multiply (x+2) by 1. However, there's a catch, which is that we subtract whatever we multiply (x+2) by, so we have to multiply it by -1 instead. We still need to cross out (22+c)x. Multiplying (x+2) by -1, we get
(-x-2) but by subtracting the whole thing from something means that we have to add -(-x-2)=x+2 to something to get 0. x+2-x-2=0, xo (22+c)x-2 must equal -x-2, meaning that (22+c)=-1 and c=-23
8.726 is rounded from the nearest whole number because if you subtract 42,900 from 24.4 and then rounded it it would be 8.726
