I know how to help you, but I need the story attached for me to help.
pertama menemukan tempat di mana dua persamaan mencegat<span>
2x+5y=1
x-3y=-5
</span>
kalikan persamaan kedua ( x - 3y = -5 ) oleh -2
-2x+6y=10
<span>tambahkan dua persamaan bersama-sama
2x+5=1
<u>-2x+6y=10 +</u>
0x+11y=11
</span>
11y=11
<span>membagi kedua sisi dengan 11
y=1
</span>
subsitute y = 1 untuk y dalam semua persamaan untuk memecahkan x
x-3y=-5
x-3(1)=-5
x-3=5
x=8
x=8
y=1
(x,y)
<span>titik persimpangan adalah ( 8,1 )
</span>
<span>untuk membuat menemukan garis tegak lurus lebih mudah , mengkonversi persamaan terakhir ke bentuk lereng - intercept
2x-y+5=0
2x+5=y
y=2x+5
</span>
<span>garis tegak lurus memiliki kemiringan yang , bila dikalikan dengan kemiringan garis lainnya , memberikan -1
y=mx+b
m=</span>lereng
y=2x+5
2 <span>dikalikan x=-1
x=-1/2
y=-1/2x+b
</span><span>subsitute ( 8,1 ) ke dalam persamaan dan memecahkan untuk b
x=8
y=1
1=-1/2(8)+b
1=-4+b</span>
tambahkan 4 untuk kedua belah pihak
5=b
<span>persamaan adalah y=-1/2+5
</span>
<span>( Catatan : Saya menggunakan google translate )</span>
5. You have correctly shown the decimal equivalents of the numbers in selection C. Those are in order. The decimal equivalents for selection D would be
... -1.33, -2.00, -1.00, -0.08, -0.07
The first of these is greater than the second of these, so this list is not in order. The correct choice is D.
6. √169 = 13, the only rational number in the lot. The correct choice is C.
8. All the numbers except the ones with radicals are rational numbers, so the appropriate choice is the one that lists the radicals only: G.
9. You have correctly plotted the points. When you connect them to make a geometric figure, you get a triangle that is 6 units high and 6 units wide. Its area will be half that of a square that is 6×6, so is 18 square units.
_____
The formula for the area of a triangle is
... A = (1/2)bh
where b is the base length of the triangle (6 units), and h is the height (6 units). Filling in the numbers you have, this is
... A = (1/2)·6·6 = 18 . . . . square units.
When you have a plot like this on a graph, it is usually pretty easy to see that the triangle area is half the area of a rectangle (or square) with the same height and width.
