Câu 1: $a)15x=-75$
$<=> x = 5$
.
$b) 3|x|=18$
$<=> |x| = 6$
$<=> x =6 hoặc x=-6$
.
$c) 2x-35=15$
$<=>2x = 50$
$<=> x= 25$
.
d) $3x+17=2$
$<=> 3x = -15$
$<=> x = -5$
.
e) $|x-1|=0$
$<=> x-1=0$
$<=> x = 1$
.
2) $a) (-4).(-5).(-6) = -120$
$b) (-3+6).(-4) = 3.(-4) = -12$
c) $(-3-5).(-3-5) =(-8)(-8) = 64$
d)$(-5-13):(-6) = (-18) : (-6) = 3$
e)$(-7)³ =-343$
f) $5^4=625$
g)$ (-4)² = 16$
.
3) $a)[(-13+(-15)]+(-8)$
= $(-28) + (-8)$
= $ -36$
.
b) $500-(-200)-210-100)$
= $500 + 200 - 210 - 100$
= $390$
.
c) $(-129)+(-199)-301+12$
= $-617$
.
d)$777-(-111)-(-2220+20)$
= $888 +2200$
= $3088$