Will mark ! which equation represents: "four times an unknown integer, multiplied by three times the unknown integer plus a different unknown integer, equals 100." a) 12x^2 + 4xy + 100 = 0 b) 12x^2 − 4xy + 100 = 0 c) 12x^2 + 4xy − 100 = 0 d) 12x^2 − 4xy − 100 = 0

12x²+4xy-100=0. The equation that represents the statement of the problem is 12x²+4xy-100=0.

The equation is represents by  "Four times an unknown integer, multiplied by three times the unknown integer plus a different unknown integer, equals 100."

First, we have the statement "four times an unknown integer", this is:

4x

Then, multiplied by three times the unknown integer plus a different unknown integer, that is:

4x(3x+y)

And finally, the equation above is equals to 100.

4x(3x+y)=100

Operating

(4x)(3x)+(4x)(y)=100

12x²+4xy=100

Then,  subtracting 100 on both sides of the equation.

12x²+4xy-100=100-100

Obtaining

12x²+4xy-100=0

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

your answer is  

a.

5

step-by-step explanation: