a) x/7 + (-3/7)^2 = 2/7 : 4/3 b) ( x – 3 ² ) ³ = ( 3 ³) ² 12/08/2021 Bởi Anna a) x/7 + (-3/7)^2 = 2/7 : 4/3 b) ( x – 3 ² ) ³ = ( 3 ³) ²
Đáp án:a/ $$x = \frac{3}{{14}}$$ b/$$x = {2.3^2} = 18$$ Giải thích các bước giải:a/$$\frac{x}{7} + {\left( {\frac{{ – 3}}{7}} \right)^2} = \frac{2}{7}:\frac{4}{3} < = > \frac{x}{7} + {\frac{{( – 3)}}{{{7^2}}}^2} = \frac{2}{7}.\frac{3}{4} < = > \frac{x}{7} + \frac{9}{{7.7}} = \frac{3}{{7.2}} < = > \frac{{7.2.x}}{{7.7.2}} + \frac{{9.2}}{{7.7.2}} = \frac{{3.7}}{{7.7.2}} < = > 14x + 18 = 21 < = > x = \frac{3}{{14}}$$ b/ $${(x – {3^2})^3} = {({3^3})^2} < = > {(x – {3^2})^3} = {({3^2})^3} < = > x – {3^2} = {3^2} < = > x = {2.3^2} = 18$$ Bình luận
a) x/7+(-3/7)²=2/7:4/3 x/7+9/49 =3/14 x/7=3/14-9/49 x/7=3/98 x=3.7/98 x=21/98=3/14 Vậy x=3/14 b) (x-3²)³= (3³)² (x-3)^6=(+-3)^6 Th1: x-3=3 x=3+3 x=6 Th2: x-3=-3 x=-3+3 x=0 Vậy x∈ {6,0} Bình luận
Đáp án:a/ $$x = \frac{3}{{14}}$$
b/$$x = {2.3^2} = 18$$
Giải thích các bước giải:a/$$\frac{x}{7} + {\left( {\frac{{ – 3}}{7}} \right)^2} = \frac{2}{7}:\frac{4}{3} < = > \frac{x}{7} + {\frac{{( – 3)}}{{{7^2}}}^2} = \frac{2}{7}.\frac{3}{4} < = > \frac{x}{7} + \frac{9}{{7.7}} = \frac{3}{{7.2}} < = > \frac{{7.2.x}}{{7.7.2}} + \frac{{9.2}}{{7.7.2}} = \frac{{3.7}}{{7.7.2}} < = > 14x + 18 = 21 < = > x = \frac{3}{{14}}$$
b/ $${(x – {3^2})^3} = {({3^3})^2} < = > {(x – {3^2})^3} = {({3^2})^3} < = > x – {3^2} = {3^2} < = > x = {2.3^2} = 18$$
a) x/7+(-3/7)²=2/7:4/3
x/7+9/49 =3/14
x/7=3/14-9/49
x/7=3/98
x=3.7/98
x=21/98=3/14
Vậy x=3/14
b) (x-3²)³= (3³)²
(x-3)^6=(+-3)^6
Th1: x-3=3
x=3+3
x=6
Th2: x-3=-3
x=-3+3
x=0
Vậy x∈ {6,0}