Toán Tìm x, biết: (x+1)+(2x+3)+(3x+5)+…+(100x+199)=30200 23/07/2021 By Everleigh Tìm x, biết: (x+1)+(2x+3)+(3x+5)+…+(100x+199)=30200
(x+1)+(2x+3)+(3x+5)+…+(100x+199)=30200 =(x+2x+3x+……….+100x)+(1+3+5+……+199)=30200 =x.(1+2+3+………+100)+(1+3+5+…….+199)=30200 =>5050x+10000=30200 =>5050x=30200-10000 =>5050x=20200 =>x=20200:5050 =>x=4 Trả lời
Đáp án:
Giải thích các bước giải:
(x+1)+(2x+3)+(3x+5)+…+(100x+199)=30200
=(x+2x+3x+……….+100x)+(1+3+5+……+199)=30200
=x.(1+2+3+………+100)+(1+3+5+…….+199)=30200
=>5050x+10000=30200
=>5050x=30200-10000
=>5050x=20200
=>x=20200:5050
=>x=4