X + 5 + 11x = 12x + y
Simplify: 12x + 5 = 12x + y (We are adding x and 11x on the left side)
Subtract 12x from each side makes each zero.
5 = y
So we can plug in and test. I'm picking two random numbers to plug in for x. 10, and 82
x = 10, y = 5
10 + 5 + 11(10) = 12(10) + 5
125 = 125
x = 82, y = 5
82 + 5 + 11(82) = 12(82) + 5
989 = 989
So we verified y = 5
Answer:
Lets take all factors into consideration first
The door is a rectangle and the area of a rectangle is length times width
Let the width be w
Let the length be l
Equation length × breadth = area
(w+48)w = 3024
w^2 + 48w = 3024
w^2 + 48w - 3024 = 0
w^2 + 84w - 36w - 3024 = 0
w(w + 84) -36 ( w + 84) = 0
(w + 84) (w - 36) = 0
w + 84 = 0 AND w - 36 =0
w = -84 and w = 36
Since width cannot be negative, the right answer is 36
How did I get 84 and 36? Well, I had to factorize 3024 and since 84 times 36 is 3024 and 84 minus 36 is 48, I chose them.
Using the Sine Rule:-
20 /sin 45 = BC / sin 30
BC = 20 sin 30 / sin45
= 20 * 1/2 / 1 / sqrt2
= 20 * 1/2 * sqrt2
= 10 sqrt2 answer
