Question

Solve the Equation 12x-14y=-8 -8x-14y=-52

Answer 1

Answer:

$\large\boxed{x=\dfrac{11}{2},\ y=\dfrac{86}{35}}$

Step-by-step explanation:

$\left\{\begin{array}{ccc}12x-14y=-8\\-8x-14y=-52&\text{change the signs}\end{array}\right\\\underline{+\left\{\begin{array}{ccc}12x-14y=-8\\8x+14y=52\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad20x=44\qquad\text{divide both sides by 20}\\.\qquad x=\dfrac{44:4}{20:4}\\\\.\qquad x=\dfrac{11}{5}\\\\.\qquad\boxed{x=2.2}\\\\\text{Put the value of x to the second equation}\ 8x+14y=52:$

$8(2.2)+14y=52\\17.6+14y=52\qquad\text{subtract 17.6 from both sides}\\14y=34.4\qquad\text{divide both sides by 14}\\y=\dfrac{34.4:2}{14:2}\\\\y=\dfrac{17.2\cdot10}{7\cdot10}\\\\y=\dfrac{172:2}{70:2}\\\boxed{y=\dfrac{86}{35}}$