Answer:
Use the quadratic formula
=
−
±
2
−
4
√
2
x=\frac{-{\color{#e8710a}{b}} \pm \sqrt{{\color{#e8710a}{b}}^{2}-4{\color{#c92786}{a}}{\color{#129eaf}{c}}}}{2{\color{#c92786}{a}}}
x=2a−b±b2−4ac
Once in standard form, identify a, b, and c from the original equation and plug them into the quadratic formula.
5
2
−
4
1
+
8
=
0
5x^{2}-41x+8=0
5x2−41x+8=0
=
5
a={\color{#c92786}{5}}
a=5
=
−
4
1
b={\color{#e8710a}{-41}}
b=−41
=
8
c={\color{#129eaf}{8}}
c=8
=
−
(
−
4
1
)
±
(
−
4
1
)
2
−
4
⋅
5
⋅
8
√
2
⋅
5
2
Simplify
3
Separate the equations
4
Solve
Solution
=
8
=
1
5
True because it is used to collect information on data tables and other things.
Answer:
The length of DE is 14 cm.
Step-by-step explanation:
Given in triangle ABC segment DE is parallel to the side AC . (The endpoints of segment DE lie on the sides AB and BC respectively). we have to find the length of DE.
Given lengths are AC=20cm, AB=17cm, and BD=11.9cm
In ΔBDE and ΔBAC
∠BDE=∠BAC (∵Corresponding angles)
∠BED=∠BCA (∵Corresponding angles)
By AA similarity rule, ΔBDE~ΔBAC
∴their corresponding sides are in proportion
⇒ 
⇒ 
⇒ 
⇒ 
Step-by-step explanation:
there are 2 similar triangles : ABE and DCE
that means they have the same angles, and the scaling factor from one triangle to the other is the same for every side.
and that means that
DE/AE = EC/BE (= DC/AB)
we know that
AE = AD + DE
BE = BC + EC
a.
so, we have actually
DE/(AD+DE) = EC/(BC+EC)
DE/(10+DE) = 8/(2+8) = 8/10 = 4/5
DE = 4(10+DE)/5
5DE = 4(10+DE) = 40 + 4DE
DE = 40 cm
b.
AD/DE = 3/5
BC/EC must be 3/5 too.
15/EC = 3/5
15 = 3EC/5
75 = 3EC
EC = 25 cm
