解答下列各题: (1)计算:-24÷(-2)×14+(-1)2-3-27; (2...

Question

解答下列各题: (1)计算:-24÷(-2)×14+(-1)2-3-27; (2)解方程:x+12-3x-18=1; (3)先化简,再求值:(2x-1)-8(2-x+24),其中x=54.

Answer 1

(1)原式=-16×(-
1
2
)×
1
4
+1+3=6;
(2)去分母得:4(x+1)-(3x-1)=8
去括号得:4x+4-3x+1=8
移项合并同类项得:x=3;
(3)原式=2x-1-16+2(x+2)=4x-13,
当x=
5
4
时,原式=-8.