X : 7 = 100 + 8 X x 7 = 357

2 câu trả lời

a) ${x:7=100+8}$

${x:7=108}$

${x=108×7}$

${x=756}$

b) 

 ${x×7=357}$

${x=357:7}$

${x=51}$

$x:7=100+8$

$x:7=108$

$x=108×7$

$x=756$

·····················

$x×7=357$

$x=357:7$

$x=51$