−9x+y= \,\,71 71 -x-y= −x−y= \,\,-1 −1 \mathbf{Add}\text{ to eliminate }\mathbf{y.}Add to eliminate y. \mathbf{Subtract}\text{ to eliminate }\mathbf{x.}Subtract to eliminate x. \mathbf{Subtract}\text{ to eliminate }\mathbf{y.}Subtract to eliminate y. \mathbf{Add}\text{ to eliminate }\mathbf{x.}Add to eliminate x.

Add to eliminate y.

Step-by-step explanation:

Given the equations

-9x + y =  71 1

-x - y = -1 2

Using elimination method we can eliminate y first since they have the same coefficient.

To do that we will need to add up both equations. We are adding because the coefficient of y in both equations has different signs. If they have the same sign, we would have subtracted.

Hence the correct option in this case is to add to eliminate y.

Intersecting secant-tangent theorem states that if a tangent segment and a secant segment are drawn to a circle from an exterior point, then the square of the measure of the tangent segment is equal to the product of the measures of the secant segment and its external secant segment.so to break it down: 1. pq acts as the tangent and ps as the secant with an intersection at p.sr = 21rp = 3x + 3pq = 4x + 4following to equation: tangent squared = the two segments multiplied by each otherso (4x + 4) ^ 2 = (3x + 3) • (21) simplifies to 16x^2 - 31x - 47 = 0 or (16x - 47)(x + 1) x = -1 or x = 47/162. pq acts as the tangent and ps as the secant with an intersection at p (again! )sr = 16rp = xpq = 15(15) ^ 2 = 16 • x225 = 16xx = 225/163. the interesting chords are proportional to each other so a ratio is possible to set up: ap dp 10 3 + x = = —— = pc pb 8 xcross multiple to get 10x = (3 + x)(8)x = 12