College

Dados los ángulos [tex]$a=3x+50$[/tex] y [tex]$f=2x+20$[/tex], determina su valor.

A. [tex]$a=116, f=64$[/tex]
B. [tex]$a=150, f=30$[/tex]
C. [tex]$a=50, f=20$[/tex]
D. [tex]$a=100, f=80$[/tex]

Answer :

We are given two angles in terms of the variable [tex]$x$[/tex]:

[tex]$$
a = 3x + 50 \quad \text{and} \quad f = 2x + 20.
$$[/tex]

If these two angles are supplementary, then their sum is [tex]$180^\circ$[/tex]. This gives us the equation:

[tex]$$
a + f = 180.
$$[/tex]

Substitute the expressions for [tex]$a$[/tex] and [tex]$f$[/tex]:

[tex]$$
(3x + 50) + (2x + 20) = 180.
$$[/tex]

Combine like terms:

[tex]$$
5x + 70 = 180.
$$[/tex]

Solve for [tex]$x$[/tex] by subtracting [tex]$70$[/tex] from both sides:

[tex]$$
5x = 180 - 70 = 110.
$$[/tex]

Divide both sides by [tex]$5$[/tex]:

[tex]$$
x = \frac{110}{5} = 22.
$$[/tex]

Now substitute [tex]$x = 22$[/tex] back into the expressions for [tex]$a$[/tex] and [tex]$f$[/tex].

For [tex]$a$[/tex]:

[tex]$$
a = 3(22) + 50 = 66 + 50 = 116.
$$[/tex]

For [tex]$f$[/tex]:

[tex]$$
f = 2(22) + 20 = 44 + 20 = 64.
$$[/tex]

Thus, the angles are:

[tex]$$
a = 116^\circ \quad \text{and} \quad f = 64^\circ.
$$[/tex]

The correct answer is option (a).