Đáp án_Giải thích các bước giải:
`a) 70:(x-3)=(3^4-1):4-10`
`x-3=70:[(81-1):4-10]`
`x =70:(80:4-10)+3`
`x =70:(20-10)+3`
`x =70:10+3`
`x =7+3`
`x =10`
Vậy `x=10`
`b) 75:(x+2)=5^3-(3^2+4^2)*2^2`
`x+2=75:[125-(9+16)*4]`
`x =75:(125-25*4)-2`
`x =75:(125-100)-2`
`x =75:25-2`
`x =3-2`
`x =1`
Vậy `x=1`
`c) 260:(x+4)=5(2^3+5)-3(3^2+2^2)`
`x+4=260:[5(8+5)-3(9+4)]`
`x =260:(5*13-3*13)-4`
`x =260:13(5-3)-4`
`x =260:13*2-4`
`x =260:26-4`
`x =10-4`
`x =6`
Vậy `x=6`
`d) (2^2+3)(x-5)+14=5^2+124:2^2`
`(4+3)(x-5)=25+124:4-14`
`7(x-5)=25+31-14`
`x-5=(42)/(7)`
`x =6+5`
`x =11`
Vậy `x=11`