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.
So the kindergartner could show animals pictures. XD JK
Answer:
197 leis left over
Step-by-step explanation:
14 times 212 = 2968
2968/30 = 98.93
212 times 0.93 = 197
98 packages and 197 leis left over
Answer:
x = 1 y = 2
Step-by-step explanation:
x + 3y = 7
- Subtract x from both sides.
3y = -x + 7
- Divide both sides by 3 to isolate the variable.
y = -1/3x + 7/3
- Plug the value of y into the other equation.
3x + 4(-1/3x + 7/3) = 11
3x - 4/3x + 28/3 = 11
- Add like terms.
5/3x + 28/3 = 11
5/3x = 5/3
x = 1
- Plug the value of x into the equation.
x + 3y = 7
(1) + 3y = 7
3y = 6
y = 2
