A 25+(x–25).5=5. 4 mũ 2 B 3.(x+3)+19=7 mũ 2 C x mũ 2=81 d x=[(1800+600):30]=560:(315-35) 08/07/2021 Bởi Gabriella A 25+(x–25).5=5. 4 mũ 2 B 3.(x+3)+19=7 mũ 2 C x mũ 2=81 d x=[(1800+600):30]=560:(315-35)
A,25+(x-25).5=5. 4² ⇔25+(x-25).5=5.4.4 25+(x-25).5=20.4 25+(x-25).5=80 (x-25).5=80-25 (x-25).5=55 x-25=55:5 x-25=11 x=11+25 x=36 B,3.(x+3)+19=7² ⇔3.(x+3)+19=7.7 3.(x+3)+19=49 3.(x+3)=49-19 3.(x+3)=30 x+3=30:3 x+3=10 x=10-3 x=7 C,x²=81 ⇔x.x=81 x=9 D,x:[(1800+600):30]=560:(315-35) x:[2400:30]=560:280 x:80=2 x=80.2 x=160 Bình luận
Đáp án:
Giải thích các bước giải:
A,25+(x-25).5=5. 4²
⇔25+(x-25).5=5.4.4
25+(x-25).5=20.4
25+(x-25).5=80
(x-25).5=80-25
(x-25).5=55
x-25=55:5
x-25=11
x=11+25
x=36
B,3.(x+3)+19=7²
⇔3.(x+3)+19=7.7
3.(x+3)+19=49
3.(x+3)=49-19
3.(x+3)=30
x+3=30:3
x+3=10
x=10-3
x=7
C,x²=81
⇔x.x=81
x=9
D,x:[(1800+600):30]=560:(315-35)
x:[2400:30]=560:280
x:80=2
x=80.2
x=160