Let's just quickly note that the area of a triangle is base*height/2
So let's use XY as the base and use Z for the height
The base, or length of XY is 9 because the x values are the same(-5) and the y values are 9 apart(-1-(-10)=9)
Thus we now know our base is 9.
Now let's figure out the height.
In the graph, draw a perpendicular line from Z to line XY. You will find that the length of the line drawn is actually the change in X from Z to X or Y.
Thus, the change of X between -9 and -5 is 4 because -5-(-9)=4.
Before I continue, I want to note that it could be -9-(-5)=-4 but it really doesn't matter because we are trying to find the distance between the tho points and distance can't be negative.
Now to continue:
We have the height, which is 4 units, and we have the length, which is 9 units. Thus we plug this into our formula to get A=H*B/2=4*9/2=18 units^2
24,10,26. Basically if you multiply each of the sides by the same number, (I multiplied everything by 2) then that will keep the ratios the same. You should be able to multiply each side by any number, but two will usually be the easiest
X2 = x2 + 2x + 9 Now subtract x2 from both sides and you have
x2- x2 = x2 - x2 + 2x + 9 or 0 = 2x + 9 now subtract 9 from both sides so you can solve for x.
0 -9 = 2x -9...and you have -9 = 2x
Now solve for x by dividing both sides by 2 and you arrive at x = -4.5
Given- 90% of runner completed the marathon.
out of which 30% are man.
To proof - let the total number of runner be y.
the men completed the marathon be 30% of the 90%.
thus we have
30% of 90% of y = 270
×
×y = 270
now solving the above equation
we get

Thus solving the equation
y = 1000
Thus the total runners of men who completed marathon be 1000.
Hence proved