Answer:
5 cm
Step-by-step explanation:
We khow that the altitude of this triangle is 1cm shorter than the base
- Let H be our altitude and B our base and A the area of the triangle
- A= (B*H)/2 ⇒ 15=(B*H)/2
- H is 1cm shorter than B ⇒ B=H+1
- H*(H+1)/2=15 ⇒ H*(H+1)=30⇒ H²+H=30⇒H²+H-30+0
that's a quadratic equation . Let's calculate the dicriminant .
Let Δ be the dicriminant
- a=1
- b=1
- c= -30
- Δ=b²-4*a*c = 1²-4*1*(-30)=1+4*30=121≥0
- Δ≥0⇔ that we have two solutions x and y
- x= (-1-
)/2= (-1-11)/2= -6 - y= (-1+)/2= 10/2 = 5
We have a negative value and a positive one
The altitude is a distance so it can't be negative
H= 5cm
D because is the equal to the other side but added allá together
Answer:
This is very detailed as I wish to make some principles about fractions clear.
3
5
12
Explanation:
This question boils down to
3
2
3
−
1
4
A fractions structure is that of:
count
size indicator of what you are counting
→
numerator
denominator
You can not directly add or subtract the counts (numerators) unless the size indicators (denominators) are the same.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Consider
3
2
3
Write as
3
+
2
3
Multiply by 1 and you do not change the value. However, 1 comes in many forms so you can change the way something looks without changing its true value
[
3
×
1
]
+
2
3
[
3
×
3
3
]
+
2
3
9
3
+
2
3
=
11
3
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Putting it all together
3
2
3
−
1
4
→
11
3
−
1
4
But the size indicators are not the same. I chose to make them become 12
11
3
−
1
4
→
[
11
3
×
1
]
−
[
1
4
×
1
]
→
[
11
3
×
4
4
]
−
[
1
4
×
3
3
]
→
44
12
−
3
12
Now we may subtract the counts
→
44
−
3
12
=
41
12
But this is the same as
12
12
+
12
12
+
12
12
+
5
12
=
1
2
+
2
1
2
+
2
1
2
+
5
12
=
3
5
12
Step-by-step explanation:
3x+3 = x-1
2x+3 = -1 (subtracted x from both sides)
2x = -4 (subtracted 3 from both sides)
x = -2 (divided 2 from both sides).
Answer: Conifers
Step-by-step explanation:
Conifers are the only living specie of gymnosperms and are cone bearing seed plants which are needle like and evergreen. Conifers produce pinecones and are common in the cold and boreal region. They are good timbers trees and are used for ornamental purposes. Conifers are the most important and diverse class of gymnosperms with about 588 living species. Examples are pines, cypresses, etc.
