Answer:
B
Step-by-step explanation:
Answer:
Yes
Step-by-step explanation:
I don't know the question but 2/3 is a real number.
Answer:
Step-by-step explanation:
1. x+2y=6 or x=6-2y
3x-2y=2
3(6-2y)-2y=2
18-6y-2y=2
18-8y=2
-8y=-18+2
-8y=-16
y=-16/-8
y=2 ans.
x+2*2=6
x+4=6
x=6-4=2 ans.
Proof:
3*2-2*2=2
6-4=2
2=2
I leave the rest for you to practice with.
3. 4x+y=7
2x+5y=-1
5. 3x+2y=-2
6x-y=6
Solve the system using the elimination method. Show all your steps.
7. -3x+3y=3
3x+y=9 add.
---------------------------------
4y=12
y=12/4
y=3 ans.
3x+3=9
3x=9-3
3x=6
x=6/3
x=2 ans.
Proof:
-3*2+3*3=3
-6+9=3
3=3
I'll leave the rest for practice.
9. -5x+12y=20
x-2y=-6
11. 3x+2y=1
4x+ 6y= 7
Theorem of cosine:
a²=b²+c²-2bc(cos α) ⇒cos α=-(a²-b²-c²) / 2bc
In this case:
a=15 cm
b=10 cm
c=5 cm
cos α=-(15²-10²-5²) / 2*10*5
cos α=-100 / 100
cos α=-1
A=arc cos -1=180º This is impossible, because:
A+B+C=180º; then B=C=0º This is impossible for make a triangle (B>0 and C>0 if we want to make a triangle).
Therefore: it is not possible can make a triangle with side lengths of 5 cm, 10 cm and 15 cm.