Question

ce valoare nunerica au literele?42:a×a:a+a=13; a=?;

Answer 1

[tex]42:a*a:a+a=13 [/tex]
[tex]42:a*1+a=13 [/tex]
[tex]42:a+a=13 [/tex]

[tex] \frac{42}{a}+a=13 42+a^2=13a [/tex]

$a^2-13a+42=0$

Δ = b² - 4ac
Δ = 13² - 4*42
Δ = 169 - 168
Δ = 1

$a_1=\frac{-b+ \sqrt{delta} }{2a} = \frac{13+1}{2}=\frac{14}{2}=7$
$a_2=\frac{-b- \sqrt{delta}}{2a} = \frac{13-1}{2}=\frac{12}2=6$

R: a∈{6;7}