There are 63 students in the room, this is because 21 time 3 gives you 63.
Answer:
I would change 2x+4y=24 into x=12–2y
To do that, divide both sides by 2 and then subtract 2y on each side.
After that, substitute for x. 3x+2y=19 would become 3(12–2y)+2y=19.
Then solve.
3(12–2y)+2y=19
36–6y+2y=19
-4y+36=19
-4y=-17
y=4.25
Then, substitute y in either equation.
Either this:
3x+2y=19
3x+2(4.25)=19
3x+8.5=19
3x=10.5
x=3.5
Or:
2x+4y=24
2x+4(4.25)=24
2x+17=24
2x=7
x=3.5
Or you could solve it in the equation you created in the beginning:
x=12–2y
x=12–2(4.25)
x=12–8.5
x=3.5
The coordinates where the lines intercept are (3.5, 4.25).
Sorry for the long answer!
Step-by-step explanation:
12. Cos 60° = 8/c
0,5 = 8/c
0,5 c = 8
c = 16
D² = V16²-8²
= V256-64
=V192 = V16×12 = 4V12
= 4V4×3 = 8V3
13. Cos 30° = 6/b
V3/2 = 6/b
V3 b = 12
b = 12/V3
b/Sin B = a /sin A
b/Sin90° = 6/ sin 60°
<u>b</u> = <u> </u><u> </u><u> </u><u>6</u><u> </u><u> </u><u> </u>
1 V3/2
b× <u>V3</u> = 6
2
b = 6× 2/V3
= 12/V3
Make the denominator the same, so multiple 3/10 by 2, which produces 6/20. Take 6/20 and subtract 7/20 because adding a negative number is the same as subtracting a positive number. the Answer is -1/20.
Answer:
please type out question as unclear to see :)