The sum of two numbers is 63, and their difference is 7. find the numbers. use x-(63-x)=7

The two numbers are 28 and 35.

Step-by-step explanation:

x + y = 63  

x - y = 7  

Get one equation with one variable. We can't solve for a variable if we had two variables in one equation.

Add the two equations together.  

2x = 70  

x = 35  

You see, the y's canceled out and we can solve for x.  

Now plug x back in to solve for y.  

35 - y = 7  

-y = -28  

y = 28  

i think 1: 2

step-by-step explanation:

- "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."