Is there a graph or something?
You can start with the form
∆y(x -x1) -∆x(y -y1) = 0
Here, we have
∆y = 11-(-3) = 14
∆x = -3-1 = -4
and we can choose (x1, y1) = (1, -3). This gives
14(x -1) -(-4)(y -(-3)) = 0
14x +4y -2 = 0
All these terms have a common factor of 2 that we can remove. Adding 1 to the result puts it in standard form:
7x +2y = 1
Answer:
You can decide where to put the first digit because you know 153 doesn't fit into 6 or 61. But you know it can fit into 613. You put it there.
50% because you first subtract the original price from the new price so 126-84 equals 42 then you divide that by the original price 84 which will give you .5 which turns to 50%
7x^2 - 16x - 8 = 0
using the quadratic formula x = [ -(-16)+/- sqrt((-16^2 - 4*7-8] / 2*7
= (16 +/1 sqrt 480) / 14
= 2.71, -0.42 to nearest hundredth