a + c + x = 120
c + x + d =125
x + d + a = 154
Tính a , c , x
0 bình luận về “a + c + x = 120
c + x + d =125
x + d + a = 154
Tính a , c , x”
$a + c + x = 120(1)\\ c + x + d =125(2)\\ x + d + a = 154(3)\\ (2)-(1)<=>d-a=5\\ (3)<=>d+a=154-x\\ =>\left\{\begin{array}{l} d=\dfrac{159-x}{2}\\ a= \dfrac{149-x}{2}\end{array} \right.\\ (3)<=>x+\dfrac{159-x}{2}+\dfrac{149-x}{2}=154=>x=13\\ =>d=73;a=68=>c=39$
$a + c + x = 120(1)\\ c + x + d =125(2)\\ x + d + a = 154(3)\\ (2)-(1)<=>d-a=5\\ (3)<=>d+a=154-x\\ =>\left\{\begin{array}{l} d=\dfrac{159-x}{2}\\ a= \dfrac{149-x}{2}\end{array} \right.\\ (3)<=>x+\dfrac{159-x}{2}+\dfrac{149-x}{2}=154=>x=13\\ =>d=73;a=68=>c=39$