(15-15/7-15/2)/(3-3/7-3/12)
15-15/7-15/2 phan 3-3/7-3/12 bang... giup toi voi
\(\frac{15-\frac{15}{7}-\frac{15}{2}}{3-\frac{3}{7}-\frac{3}{12}}\)
\(=\frac{15.\left(1-\frac{1}{7}-\frac{1}{2}\right)}{3.\left(1-\frac{1}{7}-\frac{1}{2}\right)}\)mình sửa đề luôn nhé
\(=\frac{15}{3}=5\)
\(\frac{2}{7}.\frac{12}{15}+\frac{12}{15}.\frac{3}{7}+\frac{12}{15}.\frac{1}{7}+\frac{12}{15}.\frac{1}{7}\)
giải: 12/15(2/7+3/7+1/7+1/7)=12/15.7/7=12/15=4/5
\(=\frac{12}{15}.\left(\frac{2}{7}+\frac{3}{7}+\frac{1}{7}+\frac{1}{7}\right)\)
\(=\frac{12}{15}.1\)
\(=\frac{12}{15}=\frac{4}{5}\)
4 [-2(8:4)+15(-3)-(-12)
3(25:5-14:2)-5(6:2)
[-15:(-3)]-3[2(5-9):3]
-16:(-4)[7-2(15:3)]
-7[8-3(14:7)-12:(-4)]-3(-2)
2[3-9:(-3)+2(5-7)]-18:(-9)
-16:(-8)+5[3-15:5+2] (-3+4)
4.[-2(8:4) + 15(-3) - (-12)]
= 4.[-2.2 - 45 + 12]
= 4.[-4 - 45 + 12]
= 4.[-49 + 12]
= 4.[-37]
= - 148
3.(25 : 5 - 14 : 2) - 5.(6:2)
= 3.(5 - 7) - 5.3
= 3.(-2) - 15
= - 6 - 15
= -21
[-15:(-3)] - 3.[2.(5 - 9):3]
= 5 - 3.[(2.-4):3]
= 5 - 3.[-8:3]
= 5 + 24:3
= 5 + 8
= 13
4[-2(8:4)+15:(-3)-(-12)
3(25:5-14:2)-5(6:2)
[-15:(-3)]-3[2(5-9):3)]
-16:(-4)[7-2(15:3)]
-7[8-3(14:7)-12:(-4)]-3(-2)
2[3-9:(-3)+2(5-7)]-18:(-9)
-16:(-8)+5[3-15:5+2] (-3+4)
15-15/7 - 15/12 / 3-3/7-3/12
\(\frac{15-\frac{15}{7}-\frac{15}{12}}{3-\frac{3}{7}-\frac{3}{12}}\)
\(=\frac{\frac{90}{7}-\frac{15}{12}}{\frac{18}{7}-\frac{3}{12}}\)
\(=\frac{\frac{325}{28}}{\frac{65}{28}}\)
\(=\frac{35}{17}\)
\(\frac{15-\frac{15}{7}-\frac{15}{12}}{3-\frac{3}{7}-\frac{3}{12}}\)
\(=\frac{\frac{90}{7}-\frac{15}{12}}{\frac{18}{7}-\frac{3}{12}}\)
\(=\frac{\frac{325}{28}}{\frac{65}{28}}\)
\(=5\)
câu 2: quy đồng MS 2 PS sau: 4/5 và 7/3 A; 4/8 và 7/8 B; 12/15 và 35/15 C; 4/15 và 7/15 D; 11/15 và 7/15 câu 3: PS nào sau đây bằng 2? A; 13/7 B;14/7 C; 15/7 D; 8/1 câu 4: PS nào lớn hơn 1 và có Tổng của TS và MS bằng 25? A; 13/12 B; 12/13 C; 11/14 D; 16/10
Tính nhanh:
15 - 15/7 - 15/12 / 3 - 3/7 - 3/12
\(\frac{15-\frac{15}{7}-\frac{15}{12}}{3-\frac{3}{7}-\frac{3}{12}}\)
= \(\frac{15.\left(1-\frac{1}{7}-\frac{1}{12}\right)}{3.\left(1-\frac{1}{7}-\frac{1}{12}\right)}\)
= \(\frac{15}{3}\)
= 5
15-\(\frac{15}{7}\)-\(\frac{15}{12}\)
3-\(\frac{3}{7}\)-\(\frac{3}{12}\)
=15.[1-\(\frac{1}{7}\)-\(\frac{1}{12}\)]
3.[1-\(\frac{1}{7}\)-\(\frac{1}{12}\)]
=\(\frac{15}{3}\)=5
Tính
1. 6/5 - 1/4 + 4/5 - 3/4
2. 7/9 - 5/12 + 2/9 - 7/12
3. -4/15 + 5/13 - 11/15 + 8/13
4. 9/15 - 7/13 +6/15 - 6/13
5. 12/5 - 3/7 + 3/5 - 4/7
6. 6/5 - 1/4 + 4/5 - 3/4 + 1/2
7. 13/7 - 8/6 + 8/7 - 4/6 - 1/3
a -5/9 + ( 17/20 - 4/9 ) b (7/15 - 11/20 ). -25/3 c ( 5/6 - 1/2 ).(8/15 - 3/15) d 11/12 + 7/16 : -3/4 - 13/12 giup mimh voi minh tich cho
a: =-1+17/20=-3/20
b: =(28/60-33/60)*(-25/3)
=(-1/12)*(-25/3)=1/12*25/3=25/36
c: \(=\dfrac{1}{3}\cdot\dfrac{1}{3}=\dfrac{1}{9}\)