You can use the discriminant rule, which is :
b^2 -4ac
“exactly one solution” means that it is equal to zero
so:
b^2 -4(4)(9)=0
b^2 -4(36)=0
b^2 -144=0
b^2=144
square root both sides
b=12 or -12

hope this helps !

3 0

2 years ago

Read 2 more answers

Help plzzzzzzzzzzzzzzzzzzzzz

prohojiy [21]

Answer:

c = ${\boxed{\boldsymbol{29}}}$ km

Step-by-step explanation:

Here's the required formula to find the missing side of triangle by pythagoras theorem :

${\longrightarrow{\pmb{\sf{{(a)}^{2} + {(b)}^{2} = {(c)}^{2}}}}}$

$\purple\star$ a = 20 km
$\purple\star$ b = 21 km
$\purple\star$ c = ?

Substituting all the given values in the formula to find the third side of triangle :

$\begin{gathered} \quad{\longrightarrow{\sf{{(a)}^{2} + {(b)}^{2} = {(c)}^{2}}}} \\ \\ \quad{\longrightarrow{\sf{{(20)}^{2} + {(21)}^{2} = {(c)}^{2}}}} \\ \\ \quad{\longrightarrow{\sf{(20 \times 20) + (21 \times 21) = {(c)}^{2}}}} \\ \\ \quad{\longrightarrow{\sf{(400) + (441) = {(c)}^{2}}}} \\ \\ \quad{\longrightarrow{\sf{400 + 441 = {(c)}^{2}}}} \\ \\ \quad{\longrightarrow{\sf{841= {(c)}^{2}}}} \\ \\ \quad{\longrightarrow{\sf{c = \sqrt{841}}}} \\ \\ \quad{\longrightarrow{\sf{\underline{\underline{\purple{c = 29 \: km}}}}}}\end{gathered}$

Hence, the length of missing side of triangle is 29 km.

$\rule{300}{2.5}$

3 0

2 years ago

What is the perimeter of this triangle?

Sholpan [36]

Answer:

Step-by-step explanation: what triangle?

4 0

2 years ago