bài 5 tìm x
a( 5x -15).35=0 b) 32.(3x-11)=32 c) (5x-12).25=200 d) (134-2x).2017=0 e) (6x-29)-11=0 i) (3x-59) -16=0
f) 12.(2x+ 38)=504 k) 4. (2x+8)=56 g) 88-3(7+2x)=64 l) 58-3 (7+2x)=28 h) {(3x+32)-17}.2=42 m) {(5x+12)-37}:2=25
bài 4 :
bài 5 tìm x
a( 5x -15).35=0 b) 32.(3x-11)=32 c) (5x-12).25=200 d) (134-2x).2017=0 e) (6x-29)-11=0 i) (3x-59) -16=0
f) 12.(2x+ 38)=504 k) 4. (2x+8)=56 g) 88-3(7+2x)=64 l) 58-3 (7+2x)=28 h) {(3x+32)-17}.2=42 m) {(5x+12)-37}:2=25
bài 4 :
a( 5x -15).35=0 b,32.(3x-11)=32⇔5x-15=0 ⇔3x-11=32:32⇔5x=15 ⇔3x-11=1⇔x=15:5=3 ⇔3x=1+11Vậy x=3 ⇔3x=12 ⇔x=12:3=4 Vậy x=4c, (5x-12).25=200⇔5x-12=200:25⇔5x-12=8⇔5x=8+12⇔5x=30⇔x=6Vậy x=6d) (134-2x).2017=0⇔134-2x=0⇔2x=134⇔x=134:2⇔x=67Vậy x=67e) (6x-29)-11=0⇔6x-29=11⇔6x=11+29⇔6x=40⇔x=40:6⇔x=20/3Vậy x=10/3 i) (3x-59) -16=0⇔3x-59=16⇔3x=16+59⇔3x=75⇔x=75:3⇔x=25Vậy x=25f) 12.(2x+ 38)=504⇔2x+38=504:12⇔2x+38=42⇔2x=42-38⇔2x=4⇔x=4:2=2Vậy x=2k) 4. (2x+8)=56 ⇔2x+8=56:4⇔2x+8=14⇔2x=14-8⇔2x=6⇔x=2Vậy x=2g) 88-3(7+2x)=64⇔3(7-2x)=88-64⇔3(7-2x)=24⇔7-2x=24:3⇔7-2x=8⇔2x=7-8⇔2x=-1⇔x=-1/2Vậy x=-1/2l) 58-3 (7+2x)=28⇔3(7+2x)=58-28⇔3(7-2x)=30⇔7-2x=30:3⇔7-2x=10⇔2x=7-10⇔2x=-3⇔x=-3/2Vậy x=-3/2h) {(3x+32)-17}.2=42⇔(3x+32)-17=42:2⇔(3x+32)-17=21⇔3x+32=21+17⇔3x-32=38⇔3x=38+32⇔3x=70⇔x=70/3Vậy x=70/3m) {(5x+12)-37}:2=25⇔(5x+12)-37=25.2⇔(5x+12)-37=50⇔5x+12=50+37⇔5x+12=87⇔5x=87-12⇔5x=75⇔x=75:5=15Vậy x=15
Đáp án:
Giải thích các bước giải:
\(5/\\ a,\ (5x-15)\times 35=0\\ ⇔5x-15=0\\ ⇔5x=15\\ ⇔x=3\\ \text{Vậy x = 3}\\ b,\ 32\times (3x-11)=32\\ ⇔3x-11=1\\ ⇔3x=12\\ ⇔x=4\\ \text{Vậy x = 4}\\ c,\ (5x-12)\times 25=200\\ ⇔5x-12=8\\ ⇔5x=20\\ ⇔x=4\\ \text{Vậy x = 4}\\ d,\ (134-2x)\times 2017=0\\ ⇔134-2x=0\\ ⇔2x=134\\ ⇔x=67\\ \text{Vậy x = 67}\\ e,\ (6x-29)-11=0\\ ⇔6x-29=11\\ ⇔6x=40\\ ⇔x=\dfrac{40}{6}=\dfrac{20}3\\ \text{Vậy x = $\dfrac{20}3$}\\ i,\ (3x-59)-16=0\\ ⇔3x-59=16\\ ⇔3x=75\\ ⇔x=25\\ \text{Vậy x = 25}\\ f,\ 12\times (2+38)=504\\ ⇔2x+38=42\\ ⇔2x=4\\ ⇔x=2\\ \text{Vậy x = 2}\\ k,\ 4\times (2x+8)=56\\ ⇔2x+8=14\\ ⇔2x=6\\ ⇔x=3\\ \text{Vậy x = 3}\\ g,\ 88-3\times (7+2x)=64\\ ⇔3\times (7+2x)=24\\ ⇔7+2x=8\\ ⇔2x=1\\ ⇔x=\dfrac12\\ \text{Vậy x = $\dfrac12$}\\ l,\ 58-3\times (7+2x)=28\\ ⇔3\times (7+2x)=30\\ ⇔7+2x=10\\ ⇔2x=3\\ ⇔x=\dfrac{3}{2}\\ \text{Vậy x = $\dfrac32$}\\ h,\ \left [(3x+32)-17\right ]\times 2=42\\ ⇔(3x+32)-17=21\\ ⇔3x+32=38\\ ⇔3x=6\\ ⇔x=2\\ \text{Vậy x = 2}\\ m,\ \left [(5x+12)-37\right ]:2=25\\ ⇔(5x+12)-37=50\\ ⇔5x+12=87\\ ⇔5x=75\\ x=15\\ \text{Vậy x = 15}\)
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