Giải thích các bước giải:
`Câu 1:`
`a)1/2-3/4(-6/5)`
`=1/2+9/10`
`=5/10+9/10`
`=14/10`
b)4(3/5):2/3+1(1/5):√16
`=(23)/5:2/3+6/5:4`
`=(23)/5.(3/2)+6/5.(1/4)`
`=(69)/(10)+3/(10)`
`=(72)/(10)`
`=(36)/5`
`c)(2/5)^2+5(1/2)|2,5-4,5|-11`
`=4/25+(11/2).2-11`
`=4/25+11-11`
`=4/25+0=4/25`
`Câu 2:`
`a)-3/7+x=1/3`
`<=>x=1/3-(-3/7)`
`<=>x=7/(21)+9/(21)`
`<=>x=(16)/(21)`
`Vậy x=(16)/(21)`
`b)-5/8+x=(-2/5)^2`
`<=>-5/8+x=4/(25)`
`<=>x=4/(25)-(-5/8)`
`<=>x=(32)/(200)+(125)/(200)`
`<=>x=(157)/(200)`
`Vậy x=(157)/(200)`
`c)|x+3/4|-1/2=5/2`
`<=>|x+3/4|=5/2+1/2`
`<=>|x+3/4|=6/2`
`<=>|x+3/4|=3`
`<=>x+3/4=3<=>x=3-3/4<=>x=(12)/4-3/4<=>9/4`
`Hoặc x+3/4=-3<=>x=-3-3/4<=>x=-12/4-3/4<=>x=-15/4`
`Vậy x=9/4 hoặc x=-15/4`
Chúc bạn học tốt !!!
