Đáp án:
\(x=7\)
Giải thích các bước giải:
\(x.1+x.2+x.3+...+x.9=315\\ ⇔x.(1+2+3+4+5+6+7+8+9)=315\\ ⇔x.45=315\\ ⇔x=315:45\\ ⇔x=7\\ \text{Vậy x = 7}\)
chúc bạn học tốt!
Ta có :
$x.1+x.2+x.3+...+x.9=315$
$<=> x.(1+2+3 + ... + 9) = 315$
$<=> x . 45 = 315$
$<=> x = 315 : 45$
$<=> x = 7$
a cj giúp e với ah a) (37 – 17).(-5) + 23.(-13 – 17) b) (-57).(67 – 34) – 67.(34 – 57) c) (-4).(+125).(-25).(-6).(-8) d) (-98).(1 – 246) – 246.98
rút gọn biểu thức giúp mình nha!
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vị trí của nhà văn trong nền văn học của chuyện người con gái nam xương ?
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