Toán a, (x-5):3+3=24 b, 15:x+120:12=15 c, 101+(105:x-12).7=122 21/07/2021 By Abigail a, (x-5):3+3=24 b, 15:x+120:12=15 c, 101+(105:x-12).7=122
a) $(x-5):3+3=24$ $↔(x-5):3=21$ $↔x-5=21.3=63$ $↔x=63+5=68$ b) $15:x+120:12=15$ $↔15x+10=15$ $↔15x=15-10=5$ $↔x=\dfrac{5}{15}=\dfrac{1}{3}$ c) $101+(105:x-12).7=122$ $↔(105:x-12).7=122-101=21$ $↔105:x-12=21:7=3$ $↔105:x=3+12=15$ $↔x=105:15=7$ Trả lời
Đáp án: a ) x = 68 b ) x = 3 c ) x = 7 Giải thích các bước giải: a ) ( x – 5 ) : 3 + 3 = 24 → ( x – 5 ) : 3 = 21 → x – 5 = 63 → x = 68 b ) 15 : x + 120 : 12 = 15 → 15 : x + 10 = 15 → 15 : x = 5 → x = 3 c ) 101 + ( 105 : x – 12 ) . 7 = 122 → ( 105 : x – 12 ) . 7 = 21 → 105 : x – 12 = 3 → 105 : x = 15 → x = 7 Trả lời
a) $(x-5):3+3=24$
$↔(x-5):3=21$
$↔x-5=21.3=63$
$↔x=63+5=68$
b) $15:x+120:12=15$
$↔15x+10=15$
$↔15x=15-10=5$
$↔x=\dfrac{5}{15}=\dfrac{1}{3}$
c) $101+(105:x-12).7=122$
$↔(105:x-12).7=122-101=21$
$↔105:x-12=21:7=3$
$↔105:x=3+12=15$
$↔x=105:15=7$
Đáp án: a ) x = 68
b ) x = 3
c ) x = 7
Giải thích các bước giải:
a ) ( x – 5 ) : 3 + 3 = 24
→ ( x – 5 ) : 3 = 21
→ x – 5 = 63
→ x = 68
b ) 15 : x + 120 : 12 = 15
→ 15 : x + 10 = 15
→ 15 : x = 5
→ x = 3
c ) 101 + ( 105 : x – 12 ) . 7 = 122
→ ( 105 : x – 12 ) . 7 = 21
→ 105 : x – 12 = 3
→ 105 : x = 15
→ x = 7