Where the blue scribble is!
Y = -3/2x + 4...slope is -3/2
A perpendicular line will have a negative reciprocal slope. All that means is " flip " the slope and change the sign. So that means the slope we will need is 2/3...see how I flipped the slope and changed the sign.
Now we use y = mx + b....slope(m) = 2/3....(3,9)...x = 3 and y = 9.
Time to sub...we r looking for b, the y intercept.
9 = 2/3(3) + b
9 = 2 + b
9 - 2 = b
7 = b
so the perpendicular equation is : y = 2/3x + 7...but we need it in Ax + By = C form....
y = 2/3x + 7....multiply by common denominator of 3 to get rid of fractions
3y = 2x + 21...subtract 2x from both sides
-2x + 3y = 21....<== ur answer...normally, I would have multiplied this by -1 to make x positive...but that is not an answer choice
<span>No sé la forma correcta de hacerlo, pero encontrar conjuntos de dos números que pueden igualar 12, luego encontrar cuál de los encaja en la segunda ecuación correctamente.</span>
Part A:
We see that this pair of equations has 1 solution. On a graph, the solutions of 2 (or more) lines is where the lines intersect. In this case, since these lines intersect 1 time, they have 1 solution.
Part B:
As previously mentioned, the solutions of multiple lines is where the lines intersect. In this case, since they intersect at (4,4), that is the solution.
Formula: A = 2wl + 2lh + 2hw
So... : A = 2(4x8) + 2(8x3) + 2(3x4)
A = 2(32) + 2(24) + 2(12)
A = 64 + 48 + 24
<u>Answer: A = 136</u> (add them all up)
Hope this helps!!!
:)