Question

Resolver por el método de igualación. $\\ \left \{ {{} \atop {}} \right. { {5a+b= 8} \atop {3a-4b=14}} \right.$

Answer 1

Respuesta:

5a + b =8

3a - 4b = 14

despejar  EN B

5a + b =8

b = 8 -5a

$3a- 4b = 14\\-4b = 14 -3a\\4b = -14 +3a$

$b= \frac{-14+3a}{4}$

metodo de igualacion

$8 -5a = \frac{-14+3a}{4}\\\\4(8 -5a) = -14+3a\\\\32 - 20a = -14 +3a \\\\-20a -3a = -14 -32 \\\\-23a = -46\\\\-1(-23a = -46)\\\\23a = 46\\\\a= \frac{46}{23} \\\\a = 2$

remplazamos a

a=2

$b= \frac{-14+3a}{4}$

$b= \frac{-14+3(2)}{4}\\\\b= \frac{-14+6}{4}\\\\b= \frac{-8}{4}\\\\b= -2$

Comprobacion

5a + b =8

5(2) + ( -2) =8

10 -2 =8

8=8