Đáp án:a)\(\left \{ {{x=\frac{8}{3}} \atop {y=\frac{5}{9}}} \right.\)
b)\(\left \{ {{x=\frac{86}{11}} \atop {y=\frac{-8}{11}}} \right.\)
Giải thích các bước giải:
a) \(\left \{ {{2x+3y=7} \atop {x-3y=1}} \right.⇔\left \{ {{3x=8} \atop {x-3y=1}} \right.\)
⇔\(\left \{ {{x=\frac{8}{3}} \atop {y=\frac{5}{9}}} \right.\)
b)\(\left \{ {{2x+5y=12} \atop {x-3y=10}} \right.⇔\left \{ {{2x+5y=12} \atop {2x-6y=20}} \right.\)
⇔\(\left \{ {{11y=-8} \atop {x-3y=10}} \right.⇔\left \{ {{x=\frac{86}{11}} \atop {y=\frac{-8}{11}}} \right.\)
