Tìm x biết (x+2)+(4x+4)+(7x+6)+...+(25x+18)+(28x+20)=1560
(x+2)+(4x+4)+(7x+6)+...+(25x+18)+(28x+20)=1560
[x+2]+[4x+4]+[7x+6]+...+[28x+20]=1560
13=(7X-33) :12
[(7X-31):5]*36= 7236
1+2+3+4+5+...+100+X =5350
80-9(X -4) =35
(3X-21):4+108=114
[(6X-72):2-84]*14=2814
28x+12x=80
249-7(1+x)=200
20-[(x-5)*7 +4]=2
tìm x:
a,32:(3xX-2)=8
b,75:(X-18)=25
c,(15-6xX)x243=729
d,4x(X-12)+9=17
e,20-2x(X+4)=4
Tính giá trị của A:
A=1/1 x 2 x 4 + 1/2 x 4 x 5 + 1/4 x 5 x 7 + 1/5 x 7x 8 + 1/7 x 8 x10 + 1/8 x 10x 11 + 1/10 x 11x 13
18 x 9 x 4567 x 2 x 3 x 5310 x 6
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( 2 + 4+6+8 + ...+18 +20+22) +48
\(\frac{\text{18 x 123 + 9 x 4567 x 2 + 5310 x 6}}{\text{( 2 + 4 + 6 + 8 +...+ 18 +20 + 22 ) + 48}}\)
4x 25x 0,25 x1/5 x 1/2 x 6